ELECTROCHEMICAL ARRANGEMENT, ASSOCIATED BATTERY AND METHOD

Description

[0001] The present invention relates to an electrochemical assembly, of the type comprising the characteristics of the preamble of claim 1.

[0002] Electrochemical assemblies are known, for example from US2019 / 0074487. The electrochemical assembly comprises two stacks of electrochemical elements, each of which comprises an electrical connection tab. The tabs are arranged one on top of the other and are supported by a support plate arranged on both stacks. The tabs extend on either side around the edges of the support plate. The tabs and the support plate are stacked on both stacks of electrochemical elements.

[0003] Other electrochemical assemblies or electrochemical batteries are known from WO2018159618A1; EP3451409A1; WO2018126439A1; WO2018030570A1; US2016336574A1; CN205543009U; EP2866279A1; EP2953186A1; EP2500964A2; US2011076532A1; KR101233626B1; US2007105015A1; EP2330661A1 and US2006051664A.

[0004] The aim of the invention is to provide an electrochemical assembly that is easy and economical to manufacture. The aim of the invention is in particular to provide a reliable, economical and space-saving connection between the electrodes and the terminals of the electrochemical assembly.

[0005] To this end, the invention relates to an electrochemical assembly comprising the characteristics of claim 1.

[0006] According to particular embodiments of the electrochemical assembly, the latter may comprise one or more of the following characteristics: the second electrical connection tab and the second electrical connection rib extend substantially parallel to the stacking plane; the first electrical connection tab and the first electrical connection rib extend substantially parallel to the stacking plane; the central core is arranged either substantially perpendicularly or substantially parallel to a support plane defined by the first support element and the second support element; the first common connection element is fixed to the first electrical connection tab by a material bond, in particular by laser welding, and the first electrical connection tab is fixed to the first support element by a material bond, in particular by laser welding, and / or the first common connection element is fixed to the second electrical connection tab by a material bond, in particular by laser welding, and the second electrical connection tab is fixed to the second support element by a material bond, in particular by laser welding; the first common connection element comprises an electrical connection core arranged between the first electrical connection rib and the second electrical connection rib; the electrical connection core is stepped and comprises a terminal portion and a terminal portion, the terminal portion being offset towards the stack of electrochemical elements relative to the terminal portion; the first electrical connection rib and the second electrical connection rib are arranged between the first and second electrical connection tabs,and wherein the first electrical connection tab and the second electrical connection tab are disposed between the first and second support members; the first support member and the second support member are disposed between the first and second electrical connection tabs, and wherein the first electrical connection tab and the second electrical connection tab are disposed between the first electrical connection rib and the second electrical connection rib; the first stack of electrochemical cells is provided with a third electrical connection tab of a second polarity, and the second stack of electrochemical cells is provided with a fourth electrical connection tab of the second polarity, the electrochemical assembly comprising a second common connection member,electrically connecting the third electrical connection tab and the fourth electrical connection tab and adapted to electrically connect the third electrical connection tab and the fourth electrical connection tab to an electrical connection terminal of the second polarity, the second common connection element comprises a third electrical connection rib attached to the third electrical connection tab, and a fourth electrical connection rib, attached to the fourth electrical connection tab, wherein the electrochemical assembly comprises a second support member which forms a third support element and a fourth support element and which comprises at least one central core disposed between the third support element and the fourth support element,wherein the third electrical connection tab is disposed between the third electrical connection rib and the third support member, and the fourth electrical connection tab is disposed between the fourth electrical connection rib and the fourth support member, and in particular wherein the third electrical connection tab and the third electrical connection rib extend substantially parallel to the stacking plane and the fourth electrical connection tab and the fourth electrical connection rib extend substantially parallel to the stacking plane; the first common connection member and the second common connection member have an identical shape and are arranged in a plane-symmetric configuration with respect to a plane of symmetry.

[0007] The invention further relates to a battery, of the type comprising: a casing, a cover provided with an electrical connection terminal of a first polarity and preferably with an electrical connection terminal of a second polarity an electrochemical assembly, characterized in that the electrochemical assembly is an electrochemical assembly as defined above, and in that the first common connection element is electrically connected to the electrical connection terminal of the first polarity.

[0008] The invention further relates to a method for manufacturing an electrochemical assembly, comprising the following steps: providing the first stack of electrochemical elements provided with the first electrical connection tab of the first polarity, providing the first common connection element adapted to electrically connect the first electrical connection tab to the electrical connection terminal of the first polarity, arranging the first electrical connection tab between the first electrical connection rib and the first support element, and fixing and connecting the first electrical connection rib and the first support element to the first electrical connection tab.

[0009] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings, in which: [ Fig 1 ] There Figure 1 is a schematic perspective and exploded view of an electrochemical battery according to a first embodiment of the invention; [ Fig 2 ] There Figure 2 is a schematic side and exploded view of the electrochemical battery according to the first embodiment of the invention; [ Fig 3 ] There Figure 3 is a schematic front and exploded view of the electrochemical battery according to the first embodiment of the invention; [ Fig 4 ] There Figure 4 is a schematic side view and in the assembled state of the electrochemical battery according to the first embodiment of the invention; [ Fig 5 ] There Figure 5 is a sectional view along plane VV of the Figure 4 ; [ Fig 6 ] There Figure 6 is an enlarged view of detail VI of the Figure 5 ; [ Fig 7 ] There Figure 7 is a schematic view of a detail of a variant of a battery of the Figures 1 à 6 ; [ Fig 8 ] There Figure 8 is a schematic perspective and exploded view of an electrochemical battery according to a second embodiment of the invention; [ Fig 9 ] There Figure 9 is a schematic side and exploded view of the electrochemical battery according to the second embodiment of the invention; [ Fig 10 ] There Figure 10 is a schematic front and exploded view of the electrochemical battery according to the second embodiment of the invention; [ Fig 11 ] There Figure 11 is a schematic side view and in the assembled state of the electrochemical battery according to the second embodiment of the invention; [ Fig 12 ] There Figure 12 is a sectional view along plan XII-XII of the Figure 11 ; And [ Fig 13 ] There Figure 13 is an enlarged view of detail XIII of the Figure 12 .

[0010] On the Figure 1 a battery according to the invention is shown, designated by the general reference 2. In this figure, the battery 2 is shown in perspective, in the exploded state.

[0011] Battery 2 is an electrochemical battery, as used in electric vehicles. However, other areas of application for Battery 2 are conceivable, such as energy storage, electric mobility, aviation, railways.

[0012] Battery 2 comprises a housing 4, a cover 6 and an electrochemical assembly 8.

[0013] Battery 2, and therefore electrochemical assembly 8, defines the following geometric entities: PL - longitudinal plane - a plane that generally extends parallel to large faces of the casing and perpendicular to a bottom of the casing; PT - transverse plane - a plane that generally extends parallel to small faces of the casing and perpendicular to the bottom of the casing; PE - stacking plane - plane on which the electrode layers are stacked; A - central axis - the axis passing through the center of the battery and generally coinciding with the straight line generated by the section of the longitudinal plane PL and the transverse plane PT.

[0014] The or each of the PL / PT / PE planes extends in this case in a corresponding plane of symmetry of the battery.

[0015] The cover 6 is provided with an electrical connection terminal of a first polarity 14 and an electrical connection terminal of a second polarity 16. The cover 6 is in this case a substantially rectangular plate.

[0016] The electrochemical assembly 8 comprises a first stack of electrochemical elements 18 which is provided with a first electrical connection tab 20. The electrochemical assembly 8 comprises a second stack of electrochemical elements 22 which is provided with a second electrical connection tab 24. Each stack of electrochemical elements is commonly called a “Stack”.

[0017] The first stack of electrochemical elements 18 and the second stack of electrochemical elements 22 are arranged in the housing 4 and are electrically connected to each other in a parallel electrical connection.

[0018] The battery 2 may comprise any number of electrochemical elements 8.

[0019] The first electrical connection tab 20 is formed from a superposition of metal strips which are connected or formed in one piece with current collectors of the first stack of electrochemical elements 18. The second electrical connection tab 24 is formed from a superposition of metal strips which are connected or formed in one piece with current collectors of the second stack of electrochemical elements 22. This is shown schematically in the Figure 6 .

[0020] The first electrical connection tab 20 extends substantially parallel to the PE stacking plane. The second electrical connection tab 24 extends substantially parallel to the PE stacking plane. The term “substantially parallel” means parallelism within manufacturing tolerances, for example between 0° and 3°.

[0021] The or each of the electrical connection tabs is an unbent tab and is substantially flat throughout its extent.

[0022] The first stack of electrochemical elements 18 and the second stack of electrochemical elements 22 extend on either side of the PE stacking plane.

[0023] The first electrical connection tab 20 and / or the second electrical connection tab 24 are arranged on the corresponding stack of electrochemical elements on the side remote from the other stack of electrochemical elements. The first electrical connection tab 20 and / or the second electrical connection tab 24 are therefore arranged closer to a free face of the stack of electrochemical elements adjacent to the casing 4 than to the longitudinal plane PL.

[0024] The electrochemical assembly 8 comprises a first common connection element 26 (also called a “lug” or “collector”), electrically connecting the first electrical connection tab 20 and the second electrical connection tab 24. The first connection element 26 is for example formed from a folded sheet metal.

[0025] The common connection element 26 is fixed and electrically connected to the electrical connection terminal 14 and electrically connects the first electrical connection tab 20 and the second electrical connection tab 24 to the electrical connection terminal 14.

[0026] The first common connection element 26 comprises a first electrical connection rib 28 fixed to the first electrical connection tab 20, and a second electrical connection rib 30, fixed to the second electrical connection tab 24. Generally, each of the electrical connection ribs has a greater thickness than the electrical connection tab, respectively than each of the strips of the electrical connection tab, to which this rib is associated and fixed.

[0027] The first common connection element 26 comprises an electrical connection core 32 disposed between the first electrical connection rib and the second electrical connection rib.

[0028] The electrical connection core 32 comprises a terminal portion 34 and a terminal portion 36, the terminal portion being offset towards the stack of electrochemical elements 22 relative to the terminal portion 24. In this case, the electrical connection core 32 is stepped (see Figure 2 ).

[0029] The first electrical connection rib 28 and the second electrical connection rib 30 are disposed between the first and second electrical connection tabs 20, 24.

[0030] The first electrical connection rib 28 extends substantially parallel to the PE stacking plane. The second electrical connection rib 30 extends substantially parallel to the PE stacking plane.

[0031] As visible on the Figures 1 And 2, the first electrical connection rib 28, the first electrical connection tab 20, the second electrical connection rib 30, the second electrical connection tab 24 are offset from the terminal portion 36 respectively from the associated terminal 14. This leads to a compact structure of the battery 2.

[0032] The casing 4 is for example a rectangular parallelepiped casing formed of metal or a thermoplastic material. Alternatively, the casing 4 has a cylindrical shape with a circular cross-section. The casing 4 has walls which are less deformable than the walls of the stacks of electrochemical elements 18 and 22.

[0033] Furthermore, the electrochemical assembly comprises a first support member 40, in particular a single-piece member, which forms a first support element 42, a second support element 44 and which comprises a central core 46 arranged between the first support element and the second support element.

[0034] The first support element 42 and the second support element 44 define a support plane PS, which extends perpendicular to the stacking plane PE and perpendicular to the transverse plane PT (see Figure 6 ). The support plane PS is generally a plane in which the first support element 42 and the second support element 44 are located.

[0035] The first electrical connection tab 20 is arranged between the first electrical connection rib 28 and the first support element 42. The second electrical connection tab 24 is arranged between the second electrical connection rib 30 and the second support element 44. The first support element 42 and / or the second support element 44 is for example each a support tab, in particular extending parallel to the associated electrical connection tab 20, 24. Alternatively, the first support element 42 and / or the second support element 44 have a shape different from a tab shape. Generally, each of the support elements has a greater thickness than the electrical connection tab, respectively than each of the strips of the electrical connection tab, to which this support element is associated and fixed.

[0036] Each support element is adapted to support the electrical connection tab and the associated electrical connection rib during the operation of fixing the electrical connection tab to the associated electrical connection rib. In particular, the support elements prevent deformation of the electrical connection tab / electrical connection rib assembly during the welding or brazing operation. In addition, the support elements reduce the risk of holes forming in the connection tabs during the welding or brazing operation.

[0037] The associated electrical connection rib, electrical connection tab and support element therefore form a sandwich structure.

[0038] In this case, the central core 46 is arranged substantially perpendicular to the support plane PS.

[0039] In this case, the first electrical connection tab 20 and the second electrical connection tab 24 are arranged between the first and second support elements 42, 44 (see Figure 6 ).

[0040] The first common connection element 26 is fixed to the first electrical connection tab 20 by a material connection, in particular by laser welding.

[0041] The first electrical connection tab 20 is fixed to the first support element 42 by a material connection, in particular by laser welding, and in particular by the same material connection as the first common connection element.

[0042] The first common connection element 26 is fixed to the second electrical connection tab 24 by a material bond, in particular by laser welding. The second electrical connection tab 24 is fixed to the second support element 44 by a material bond, in particular by laser welding, and in particular by the same material bond as the first common connection element.

[0043] The structure of the electrical connection tabs and the electrical connection element connects the stacks of electrochemical elements along the tabs in a space-saving manner along the central axis AA.

[0044] The structure of battery 2 is substantially symmetrical.

[0045] The elements described above in association with the first polarity are also present with regard to the second polarity.

[0046] More specifically, the first stack of electrochemical elements 18 is provided with a third electrical connection tab 60 of a second polarity, and the second stack of electrochemical elements 22 is provided with a fourth electrical connection tab 64 of the second polarity.

[0047] The electrochemical assembly comprises a second common connection element 66, electrically connecting the third electrical connection tab 60 and the fourth electrical connection tab 66 and adapted to electrically connect the third electrical connection tab and the fourth electrical connection tab to the electrical connection terminal 16 of the second polarity.

[0048] The first common connection element 26 and the second common connection element 66 have an identical shape. The second common connection element 66 therefore has the same structural characteristics as the first common connection element 26.

[0049] The second common connection element 66 includes a third electrical connection rib 68 attached to the third electrical connection tab 60, and a fourth electrical connection rib 70, attached to the fourth electrical connection tab 64.

[0050] The second common connection element 66 comprises an electrical connection core 72 disposed between the third electrical connection rib and the fourth electrical connection rib.

[0051] The electrical connection core 72 comprises a terminal portion 74 and a terminal portion 76, the terminal portion 76 being offset towards the stack of electrochemical elements 22 relative to the terminal portion 24. In this case, the electrical connection core 72 is stepped (see Figure 2 ).

[0052] The electrochemical assembly 8 comprises a second support member 80, in particular a single-piece member, which forms a third support element 82 and a fourth support element 84 and which comprises at least one second central core 86 arranged between the third support element and the fourth support element.

[0053] The third electrical connection tab 60 is disposed between the third electrical connection rib 68 and the third support member, and the fourth electrical connection tab 64 is disposed between the fourth electrical connection rib 70 and the fourth support member.

[0054] The third electrical connection tab 60 and / or the third electrical connection rib extend substantially parallel to the stacking plane (PE) and the fourth electrical connection tab 64 and the fourth electrical connection rib extend substantially parallel to the stacking plane (PE).

[0055] The first common connecting element 26 and the second common connecting element 66 are arranged in a plane symmetric configuration with respect to a plane of symmetry (PT).

[0056] On the Figure 7 schematically represents a section of an electrochemical assembly according to a variant of the battery according to the invention above. This variant differs from what has been described previously only in the following. Similar elements bear the same references.

[0057] The first support element 42 and the second support element 44 are disposed between the first and second electrical connection tabs 20, 24. Also, the first electrical connection tab 20 and the second electrical connection tab 24 are disposed between the first electrical connection rib 28 and the second electrical connection rib 30.

[0058] In other words, the first support member 40 is arranged between the first electrical connection rib 28 and the second electrical connection rib 30. The configuration is therefore reversed with respect to that of the Figure 6 . In addition, the first support member 40 advantageously has the shape of a rectangular frame in order to avoid deformation during the fixing step.

[0059] It should be noted that the second support member 80 and the second common connection element 66 may have a configuration identical to that of this Figure 7 or the configuration of the Figure 6 , described above.

[0060] On the Figures 8 à 13 a second embodiment of the battery according to the invention is shown. The Figures 8 à 13 correspond to the Figures 1 à 7 . This second embodiment differs from the first embodiment only in the following. Similar elements bear the same references.

[0061] The central core 46 of the first support member 40 is arranged substantially parallel to the support plane PS.

[0062] Likewise, the central core 86 of the second support member 80 is arranged substantially parallel to the support plane PS.

[0063] Thus, the central core 46, respectively 86, is connected along the long edges of the support elements 42, 44 respectively 82, 84. Also, the central core 46, respectively 86, covers the terminal portion 34, respectively 74, of the electrical connection core 32, respectively 72, and extends parallel thereto.

[0064] As a variant of this second embodiment, the support elements 42, 44 and / or 82, 84 can be arranged as in the variant of the Figure 7 .

[0065] In a variant not shown of the embodiments described above, the common connection element, for example the element 26, comprises only a single electrical connection rib, for example the rib 28. In this case, either a single stack of electrochemical elements is connected to the common connection element, or the other stack of electrochemical elements is connected by means other than an electrical connection rib to the common connection element.

[0066] Similarly, the support member may comprise only one support element or be formed by this support element.

[0067] This is applicable, for example, to batteries 2 which only have a single stack of electrochemical elements.

[0068] Alternatively, alternatively or additionally, the or each electrical connection tab and the associated electrical connection rib extend relative to the stacking plane (PE) at an angle of between 0° and 45°.

[0069] The method of manufacturing an electrochemical assembly as defined above includes, among other things, the following successive steps: providing the first stack of electrochemical elements 18 provided with the first electrical connection tab 20 of the first polarity, providing the first common connection element 26 adapted to electrically connect the first electrical connection tab to the electrical connection terminal 14 of the first polarity, arranging the first electrical connection tab 20 between the first electrical connection rib 28 and the first support element 42, fixing and connecting the first electrical connection rib 28 and the first support element 42 to the first electrical connection tab.

[0070] Preferably, during the fixing step, the first electrical connection tab and the first electrical connection rib extend at an angle either parallel or oblique (eg between 0° and 60°) to the PE stacking plane.

[0071] The same steps are implemented for the second stack of electrochemical elements provided with the second electrical connection tab and, where applicable, for the elements of the second polarity.

[0072] In this case, the fixing and connection of the first electrical connection rib 28 and the first support element 42 to the first electrical connection tab and the fixing and connection of the second electrical connection rib 30 and the second support element 44 to the second electrical connection tab are carried out simultaneously.

[0073] The battery structure is compact while leading to a reliable electrical connection between the various elements. The battery is also easy and economical to manufacture, particularly due to the arrangement of the electrical connection tabs and the characteristics of the common connection elements and support members.

Claims

1. An electrochemical assembly of the type comprising a first stack of electrochemical elements (18) provided with a first electrical connection tab (20) with a first polarity, the first stack of electrochemical elements extending along a stacking plane (PE), a first common connection element (26) adapted to electrically connect the first electrical connection tab to an electrical connection terminal (14) with the first polarity, the first common connection element comprising a first electrical connection rib (28) fastened to the first electrical connection tab, the electrochemical assembly comprising a first support element (42), the first electrical connection tab (20) being arranged between the first electrical connection rib (28) and the first support element (42), the electrochemical assembly comprising a second stack of electrochemical elements (22) provided with a second electrical connection tab (24) with the first polarity, the second stack of electrochemical elements extending along the stacking plane (PE), the first common connection element (26) electrically connecting the first electrical connection tab and the second electrical connection tab and is suitable for connecting the second electrical connection tab to the electrical connection terminal (14) with the first polarity, the first common connection element (26) comprising a second electrical connection rib (30) fastened to the second electrical connection tab, the electrochemical assembly comprising a second support element (44), the second electrical connection tab being arranged between the second electrical connection rib and the second support element, characterized in that the electrochemical assembly comprises a first support element (40) which forms the first support element and the second support element and which comprises at least one central core (46) arranged between the first support element and the second support element.

2. The electrochemical assembly according to claim 1, wherein the first electrical connection tab and the first electrical connection rib extend substantially parallel to the stacking plane (PE).

3. The electrochemical assembly according to claim 1 or 2, wherein the second electrical connection tab and the second electrical connection rib extend substantially parallel to the stacking plane (PE).

4. The electrochemical assembly according to any of claims 1 to 3, wherein the central core is arranged either substantially perpendicular or substantially parallel to a support plane (PS) defined by the first support element and the second support element.

5. The electrochemical assembly according to any of claims 1 to 4, wherein the first common connection element (26) is fastened to the first electrical connection tab (20) by a material connection, in particular by laser welding, and the first electrical connection tab (20) is fastened to the first support element by a material connection, in particular by laser welding, and / or the first common connection element (26) is fastened to the second electrical connection tab (24) by a material connection, in particular by laser welding, and the second electrical connection tab (24) is fastened to the second support element by a material connection, in particular by laser welding.

6. The electrochemical assembly according to any of the preceding claims, wherein the first common connection element (26) comprises an electrical connection core (32) arranged between the first electrical connection rib and the second electrical connection rib.

7. The electrochemical assembly according to claim 6, wherein the electrical connection core (32) is stepped and comprises a terminal portion (36) and an end portion (34), the terminal portion being offset toward the stack of electrochemical elements with respect to the end portion.

8. The electrochemical assembly according to any of claims 1 to 7, wherein the first electrical connection rib (28) and the second electrical connection rib (30) are arranged between the first and the second electrical connection tabs, and wherein the first electrical connection tab and the second electrical connection tab are arranged between the first and the second support elements.

9. The electrochemical assembly according to any one of claims 2 to 7, wherein the first support element (42) and the second support element (44) are arranged between the first and the second electrical connection tabs, and wherein the first electrical connection tab (20) and the second electrical connection tab (24) are arranged between the first electrical connection rib and the second electrical connection rib.

10. The electrochemical assembly, according to any of the preceding claims, wherein the first stack of electrochemical elements is provided with a third electrical connection tab (60) with a second polarity, and the second stack of electrochemical elements is provided with a fourth electrical connection tab (64) with the second polarity, the electrochemical assembly comprising a second common connecting element (66), electrically connecting the third electrical connection tab and the fourth electrical connection tab and suitable for electrically connecting the third electrical connection tab and the fourth electrical connection tab to an electrical connection terminal (16) with the second polarity, the second common connecting element comprises a third electrical connection rib (68) fastened to the third electrical connection tab, and a fourth electrical connection rib (70) fastened to the fourth electrical connection tab, wherein the electrochemical assembly comprises a second support component (80) which forms a third support element (82) and a fourth support element (84) and which comprises at least one central core (86) arranged between the third support element and the fourth support element, wherein the third electrical connection tab is arranged between the third electrical connection rib (68) and the third support element (82), and the fourth electrical connection tab is arranged between the fourth electrical connection rib (70) and the fourth support element (84), and in particular wherein the third electrical connection tab (60) and the third electrical connection rib extend substantially parallel to the stacking plane (PE) and the fourth electrical connection tab (64) and the fourth electrical connection rib extend substantially parallel to the stacking plane (PE).

11. The electrochemical assembly according to claim 10, wherein the first common connecting element (26) and the second common connecting element (66) have an identical shape and are arranged according to a plane symmetry configuration with respect to a plane of symmetry (PT).

12. A battery, of the type comprising - a casing (4), - a cover (6) provided with an electrical connection terminal (14) with a first polarity and preferentially with an electrical connection terminal (16) with a second polarity - an electrochemical assembly (8), characterized in that the electrochemical assembly (8) is an electrochemical assembly according to any of the preceding claims, and in that the first common connection element (26) is electrically connected to the electrical connection terminal (14) with the first polarity.

13. The manufacturing process for an electrochemical assembly according to any of claims 1 to 11, comprising the following steps: - providing the first stack of electrochemical elements (18) provided with the first electrical connection tab (20) with the first polarity, - providing the first common connection element (26) suitable for electrically connecting the first electrical connection tab to the electrical connection terminal (14) with the first polarity, - arranging the first electrical connection tab (20) between the first electrical connection rib (28) and the first support element (42), and - fastening and connecting the first electrical connection rib (28) and the first support element (42) to the first electrical connection tab.