Laminated busbar for energy storage

Abstract

To provide a laminated busbar for interconnecting packs of prismatic electrical cells within a module from a battery.SOLUTION: Cells are organized into groups 30, and each group has the same number of cells 22. A laminated busbar 100 includes at least one conductive element 112. Each conductive element includes: a first conductive layer 110 configured to electrically connect electrodes 28 of two adjacent groups of cells; a first insulating layer 130 laminated on the first conductive layer; and a first electrical connector 114 configured to connect to a first group 30A of cells. The laminated busbar includes: a second conductive layer 140 laminated on the first insulating layer and including a second electrical connector 142 configured to connect to a last group 30B of cells; and a third electrical connector 144. The first insulating layer has a cutout window 134 configured to permit electrical connection between the last group of cells and the second electrical connector.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention generally relates to a laminated bus bar for interconnecting packs of prismatic cells within a battery, and a module for a battery including such packs and bus bars.

Background Art

[0002] Electrical energy storage systems, or batteries, are used in various situations, and battery packs are a central component of such systems. For example, a stationary electrical storage system can include a battery pack for storing energy generated from solar panels. Electrical storage systems can also be used in mobile applications such as electric vehicles. The basic unit of an electrical storage system is an electrical cell, which comes in several shapes. There are three common types of cells: pouch, prismatic, and cylindrical.

[0003] Cells have a predetermined voltage and electrical energy storage capacity depending on the cell technology and size. Therefore, in many applications, it is necessary to connect individual cells to each other using bus bars in order to construct an energy storage system that can store and supply more power than a single battery cell. Thus, energy storage systems include modules, each of which forms a pack of cells by comprising a plurality of cells assembled together, which is also referred to simply as a "pack". Different types of bus bars are used for connecting modules within a battery and for connecting cells of the same pack within a module.

[0004] Among the various types of cells that exist today, prismatic cells are widely used due to their ease of manufacture and handling. Each cell has a prismatic shape, with two accessible electrodes located on its top surface. The two electrodes include a positive and a negative electrode. The top surface is usually rectangular, with two short sides and two long sides, and each electrode is located next to its respective short side. Within a module, several prismatic cells are usually arranged together, with their top surfaces all facing the same direction and stacked along their long sides to form a row of electrical cells.

[0005] Depending on the module design, the busbars are configured to electrically connect all cells in a column in series and parallel.

[0006] Such prismatic cell interconnect busbars are a crucial component of battery modules. To reduce the global cost of battery packs, busbars must be easy to manufacture and, given the large number of individual battery cells to connect, easy to connect. Conventional busbars for battery interconnects employ both stacked busbars and / or non-stacked assemblies.

[0007] Patent Document 1 describes several designs of laminated busbars in which a conductive layer is laminated on an insulating layer. However, this is costly and time-consuming because it requires the separate placement of return circuits.

[0008] Therefore, improved busbars are needed for interconnecting prismatic electrical cells. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] U.S. Patent Application Publication No. 2016 / 073506(A1) [Overview of the Initiative]

[0010] For this purpose, aspects of the present invention relate to stacked busbars for interconnecting packs of prismatic electrical cells in a module from a battery. The stacked busbar has an elongated, flat shape that extends in the midline along the main axis, The aforementioned pack of electric cells is The aforementioned electric cells are configured to be arranged in a line along the main axis, Each cell has an upper surface with two electrodes having opposite polarity and positioned on opposite sides of a longitudinal plane parallel to the principal axis and perpendicular to the median plane, the electrodes of each cell are positioned within the median plane, and the upper surfaces of each cell are oriented in the same direction. The cell is composed of at least two groups, each group comprising the same number of electrical cells, with the cells of the first group and the cells of the last group positioned at opposite ends of the pack. Within the same group of cells, the electrodes having the same polarity are arranged on the same side of the longitudinal plane. In two adjacent groups of cells, the electrodes having the same polarity are arranged on opposite sides of the longitudinal plane. The aforementioned stacked busbars are A first conductive layer comprising at least one conductive element, each conductive element configured to electrically connect two adjacent groups of electrodes of the cell, wherein the electrodes are arranged on the same side of the longitudinal plane, A first insulating layer laminated on the first conductive layer, The device comprises a first electrical connector configured to connect to an electrode of a first group of cells that is not connected to a conductive element of the first conductive layer.

[0011] According to the present invention, The laminated busbar further comprises a second conductive layer extending along the main axis and having two ends, each equipped with a second electrical connector and a third electrical connector, The second conductive layer is laminated on the first insulating layer and electrically isolated from the first conductive layer by the first insulating layer, and the first conductive layer is sandwiched between the first insulating layer and the electrode when the laminated busbar is connected to the pack of the cell. The second electrical connector is configured to connect to an electrode of the last group of cells that is not connected to a conductive element of the first conductive layer, and the third electrical connector is closer to the first electrical connector than to the second electrical connector. The first insulating layer includes a notch window configured to allow an electrical connection between the corresponding electrodes of the last group of cells and the second electrical connector.

[0012] The busbar according to the present invention is advantageous in that it is optimized for rapid assembly of busbars into modules of electrical cells. Because the first and third connectors are readily available for connecting modules of electrical cells to other modules, only one busbar is required for interconnecting the cells in the modules, making it efficient and economical. The stacked structure contributes to reducing the cost, size, and weight of the battery module. Furthermore, it can be adapted to modules of various sizes through simple configuration changes, such as simply manufacturing the busbar to the required dimensions.

[0013] In any advantageous but arbitrary manner, such a busbar may incorporate one or more of the following functions, either alone or in any technically permissible combination: Each conductive element comprises at least two connection terminals, each having a weld area configured to be welded to each electrode of the cell, the first insulating layer having an opening configured to allow access to the weld area of ​​each connection terminal, and the second conductive layer being positioned such that the second conductive layer does not obstruct access to the opening of the first insulating layer.

[0014] For each conductive element, Two adjacent connection terminals are connected to each other by a connecting member. For two adjacent connection terminals, the conductive element includes a notch disposed between the two adjacent connection terminals, each notch extends orthogonally to the main axis, whereby each connection terminal is allowed to rotate with respect to the connecting member along a rotation axis parallel to the main axis independently of the adjacent connection terminal.

[0015] The connecting member further includes at least one flexible portion, each flexible portion extends orthogonally to the main axis and is aligned with the respective notch, and each flexible portion separates the connecting member at two adjacent connecting parts, each flexible portion is elastically deformable, whereby each connecting part rotates relative to the adjacent connecting part along a pivot axis aligned with the corresponding flexible portion.

[0016] The laminated bus bar further includes a bottom insulating layer, the bottom insulating layer is laminated on the first conductive layer, the bottom insulating layer includes an opening configured to allow electrical connection of the conductive element to the corresponding electrode.

[0017] The laminated bus bar further includes a top insulating layer, the top insulating layer is laminated on the second conductive layer, the top insulating layer includes a top opening configured to allow access to each connection terminal.

[0018] The second conductive layer is made of a metal sheet.

[0019] The second conductive layer has an overlapping area that exceeds 30%, preferably exceeds 50%, and preferably further exceeds 75% of the area of the surface of the first conductive layer.

[0020] The present invention also relates to a battery module comprising a pack of prismatic electric cells, The cells are interconnected by stacked busbars as described in any one of the above claims, The cells are arranged in a row along the main axis, Each cell has an upper surface with two electrodes having opposite polarities and positioned on opposite sides of the longitudinal plane, the electrodes of each cell are positioned within the median plane, and the upper surfaces of each cell are oriented in the same direction. The cells are composed of at least two groups, each group having the same number of cells, with the cells of the first group and the cells of the last group positioned at opposite ends of the column. Within the same group of cells, the electrodes having the same polarity are arranged on the same side of the longitudinal plane. In two adjacent groups of cells, the electrodes having the same polarity are positioned on opposite sides of the longitudinal plane.

[0021] To have an advantage, The module comprises a container configured to hold the cell, and the first connector and the third connector are arranged outside the container, preferably adjacent to each other.

[0022] The present invention will be better understood, and other advantages will be more clearly shown, in light of the following description of three embodiments of stacked busbars and battery modules, and only as non-limiting examples with reference to the accompanying drawings. [Brief explanation of the drawing]

[0023] [Figure 1] Figure 1 is a perspective view of a preferred module of a prismatic cell equipped with stacked busbars according to a first embodiment of the present invention. [Figure 2] Figure 2 is an exploded view of the module shown in Figure 1. [Figure 3] Figure 3 is an exploded view similar to Figure 2, but with some elements of the busbar hidden, and showing the first and second conductive layers of the busbar. [Figure 4]Figure 4 is a top view showing the second conductive layer and the first conductive layer of the busbar for two inserts a) and b). [Figure 5] Figure 5 is a perspective view showing the details of the conductive elements of the second conductive layer and the first conductive layer for two inserts a) and b), respectively. [Figure 6] Figure 6 is a perspective view similar to Figure 3, showing the first conductive layer and the second conductive layer of a busbar according to a second embodiment of the present invention. [Figure 7] Figure 7 is a top view similar to Figure 4, and shows the second conductive layer and the first conductive layer of the busbar according to the second embodiment for two inserts a) and b). [Figure 8] Figure 8 is a top view showing a preferred second conductive layer according to a third embodiment of the present invention. [Figure 9] Figure 9 is a top view showing a preferred second conductive layer according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0024] Next, embodiments of the present invention will be described with reference to the drawings, where similar reference numerals are used throughout to refer to similar elements. Please note that the drawings are not necessarily to a constant scale.

[0025] A first embodiment of the present invention will be described with reference to Figures 1 to 5.

[0026] A battery module 10 is shown in Figure 1. The battery is used for transportation, such as in an automobile, and is used, for example, to store electrical energy and supply electrical energy to the traction motor of an electric vehicle or a hybrid electric vehicle. According to some embodiments, the battery belongs to an electric vehicle. The battery typically comprises several modules 10 that are electrically connected to one another.

[0027] Module 10 comprises a container 12, roughly indicated by mixed wires in a box shape, a pack 20 of prismatic electrical cells 22, and a stacked busbar 100. The pack 20 is placed inside the container 12, which is configured to hold the cells 22, and therefore, within the pack 20, the cells 22 are fixed to one another. The prismatic electrical cells 22 in the pack 20 are interconnected by the stacked busbar 100, as described below. The stacked busbar 100 is also abbreviated simply as "busbar 100," and the prismatic electrical cells 22 are also abbreviated simply as "cells 22."

[0028] In the illustrated non-limiting example, pack 20 comprises eight cells 22, but in other embodiments, the number of cells 22 in each pack 20 may differ. Within the scope of this description, unless otherwise specified, “cell 22” refers to a prismatic electrical cell 22. Cells 22 in the same pack 20 have the same shape, function similarly, and are preferably identical to one another. The description of one cell 22 applies to the other cells 22 as well.

[0029] Figure 2 shows an exploded view of module 10, with container 12 omitted. In Figure 3, some elements of busbar 100 are not shown, making pack 20 more visible.

[0030] Each cell 22 has a rectangular prism shape with a rectangular cross-section projected along the cell axis A22. In the figure, the cell axis A22 is assumed to be horizontal. Each cell 22 has two sides 24, which extend perpendicular to the cell axis A22 and face in opposite directions to each other.

[0031] Each cell 22 has a top surface 26 and two electrodes 28 positioned on the top surface 26. The two electrodes 28 include a first electrode 28A and a second electrode 28B, which have opposite polarities and are distinguishable from each other. The electrodes 28 are accessible for connection to external elements, in particular to the busbar 100. In other words, the electrodes 28 of each cell 22 are configured to be electrically connected to the stacked busbar 100.

[0032] Within the pack 20, the cells 22 are stacked on top of each other along the longitudinal axis A20 of the pack 20. The cell axis A22 of each cell 22 is aligned overall with the longitudinal axis A20, and the top surface 26 of each cell 22 is oriented in the same direction as the other cells 22. For two adjacent cells 22, the first side 24 of the two cells 22 faces the other side 24 of the two cells 22.

[0033] In other words, within pack 20, the cells 22 are arranged in a row along the longitudinal axis A20, and pack 20 comprises a first cell 22A and a last cell 22B, with the first cell 22A and the last cell 22B located at the two ends of pack 20. In Figures 1 to 3, the leftmost cell 22 in the figure is the first cell 22A, and the rightmost cell 33 in the figure is the last cell 22B.

[0034] For each cell 22 of pack 20, the two electrodes 28 are positioned on opposite sides of the longitudinal plane P20 of pack 20, and the longitudinal plane P20 is perpendicular and parallel to the longitudinal axis A20.

[0035] The electrode 28 is geometrically positioned by the median plane P21 of the pack 20, which is parallel to the longitudinal axis A20 and perpendicular to the longitudinal plane P20. In the illustrated example, the upper side 26 of each cell 22 is assumed to be upward, and the median plane P21 is horizontal.

[0036] Within pack 20, the cells 22 are arranged in at least two groups 30, with the same number of cells 22 in each group 30. In the illustrated example, the groups 30 are connected in series with each other. In the first embodiment of the present invention, each group 30 contains only one cell 22. In other words, pack 20 contains eight groups 30, each containing one cell 22, and all the cells 22 are connected in series with each other.

[0037] The group 30 containing the first cell 22A is also called the first group 30A, and the group 30 containing the last cell 22B is also called the last group 30B. In other words, the first group 30A and the last group 30B are located at both ends of the pack 20. In Figures 1 to 3, the first group 30A is located on the left side, and the last group 30B is located on the right side. Also, the first group 30A is separated from the last group 30B by the other six groups 30.

[0038] Within the same group 30 of cell 22, electrodes 28 having the same polarity are located on the same side of the longitudinal plane P20. In other words, within the same group 30, the first electrode 28A is located on one side of the longitudinal plane P20, and the second electrode 28B is located on the opposite side of the longitudinal plane P20.

[0039] For two adjacent groups 30 of cell 22, electrodes 28 having the same polarity are positioned on opposite sides of the longitudinal plane P20. In other words, for two adjacent groups 30 of cell 22, the first electrode 28A of one of the two groups 30 and the first electrode 28A of the other group 30 are positioned on opposite sides of the longitudinal plane P20.

[0040] The stacked busbar 100 will be described with reference to Figures 1 to 3.

[0041] The stacked busbar 100 has an elongated, flat shape that extends into the median plane P101 along the main axis A100. The longitudinal plane A100 of the busbar 100 is also defined for convenience, and the longitudinal plane A100 is parallel to the main axis A100 and perpendicular to the median plane P101. As shown in Figure 1, when the stacked busbar 100 is connected to the pack 20, the main axis A100 is parallel to the axis A20 of the pack, the longitudinal plane P100 of the busbar 100 is almost coplanar with the longitudinal plane P20, and the median plane P101 of the busbar 100 is parallel to the median plane P21 of the pack 20.

[0042] The laminated busbar 100 comprises a first conductive layer 110, a first insulating layer 130 laminated on the first conductive layer 110, and a second conductive layer 140 laminated on the first insulating layer 130 and electrically isolated from the first conductive layer 110 by the first insulating layer 130. The first conductive layer 110 is sandwiched between the first insulating layer 130 and the electrode 28 when the laminated busbar 100 is connected to the pack of cells 20. Within the scope of this description, the first insulating layer 130 and the other insulating layers described later are each made from a material that is both flexible and electrically insulating, preferably a polymer material, such as polyester or polyimide. Each insulating layer has a thickness of 25 μm to 250 μm.

[0043] A top view of the first conductive layer 110 is also shown in insert b) of Figure 4. The first conductive layer 110 comprises at least one conductive element 112, each conductive element 112 configured to be electrically connected to electrodes 28 belonging to two adjacent groups 30 of the cell, respectively, the electrodes 28 being located on the same side of the longitudinal plane P20.

[0044] The first conductive layer 110 also includes a first electrical connector 114 configured such that the electrodes 28 are connected to the electrodes 28 of the first group 30A of cells that are not connected to the conductive elements 112 of the first conductive layer 110.

[0045] In the illustrated example, pack 20 includes eight groups 30 of cells 22, and the first conductive layer 110 includes seven conductive elements 112. The first connector 114 is connected here to the first electrode 28A of the first group 30A of cells 22.

[0046] Optionally, the first connector 114 may be provided with a mechanical interface 116, in this case a rivet, for mechanical connection of the first connector 114 to an external element such as a busbar (not shown).

[0047] The conductive elements 112 of the first conductive layer 110 function similarly, preferably have the same shape, and more preferably are identical to one another. One of the conductive elements 112 is shown enlarged on insert b) of Figure 5. The description of one of the conductive elements 112 is also valid for the other conductive elements 112.

[0048] Each conductive element 112 comprises at least two connection terminals 118, each configured to connect to one electrode 28 of the cell 22, and a connecting member 120. Within the conductive element 112, two adjacent connection terminals 118 are connected to each other by the connecting member 120. In the illustrated example, the connecting member 120 has a triangular shape, and each connection terminal 118 has a rectangular shape.

[0049] In the non-limiting illustrated example, the connection terminals 118 of each conductive element 112 are located on the same side of the longitudinal plane P100 and are configured to connect to electrodes 28 that belong to two adjacent groups 30 of the cell 22 and are located on the same side of the longitudinal plane P100. The cell 22 is a prismatic cell, and the connection terminals 118 located on the same side of the longitudinal plane P100 are aligned with each other along a direction parallel to the longitudinal plane P100. Each connecting member 120 straddles the longitudinal plane P100, and the connection terminals 118 are located away from the longitudinal plane P100.

[0050] Each connector 118 includes a welding area 122 configured to be welded to its respective electrode 28. In the illustrated example, each connector 118 preferably includes a centering hole 124 located in the central region of the connector 118, and the welding area 122 extends around the centering hole 124. In Figure 5b), each welding area 122 is schematically shown by a dotted line abbreviation.

[0051] Each centering hole 124 is configured to allow visual confirmation that the welding area 122 is properly aligned with the corresponding electrode 28 before the actual welding operation during the connection of the busbar 100 and the pack 20.

[0052] The welding process for the connection terminals 118 to each electrode 28 is preferably laser welding. During the operation of connecting the connection terminals 118 to each electrode 28, the connection terminals 118 are first mechanically pressed against the corresponding electrode 28 to ensure a good electrical connection, and then the welding itself is performed.

[0053] In the illustrated example, the first insulating layer 130 and the electrodes 28 are located on the opposite side of the first conductive layer 110. The first insulating layer 130 includes a first opening 132 configured to allow access to the weld area 124 of each connection terminal 118.

[0054] Due to manufacturing tolerances, the actual position of each electrode 28 may deviate from the theoretical position where each electrode 28 is geometrically positioned by the median plane P21.

[0055] For each conductive element 112, two adjacent connection terminals 118 are connected to each other by a connecting member 120, and the conductive element 112 is provided with a notch 126 positioned between the two adjacent connection terminals 118.

[0056] Each notch 126 extends perpendicular to the main axis A100 and is configured to facilitate the elastic deformation of the conductive element 112, so that each connecting terminal 118 is allowed to rotate relative to the connecting member 120 along a rotation axis A118 parallel to the main axis A100, independently of adjacent connecting terminals 118.

[0057] Optionally, the connecting member further comprises at least one flexible portion 128. The flexible portion 128 is schematically represented here by a fold having a semicircular cross-section. Alternatively, the flexible portion 128 is flat, manufactured, for example, by punching out the conductive element 112.

[0058] Each flexible portion 128 separates the connecting member 120 into two adjacent connecting portions 130. Each flexible portion 128 extends perpendicular to the main axis A100 and aligns with its respective notch 126. Because each flexible portion 128 is elastically deformable, each connecting portion 130 rotates relative to the adjacent connecting portion 130 along the pivot axis A130 aligned with the corresponding flexible portion 128.

[0059] Each conductive element 112 is elastically deformed in response to the positional displacement of the electrode 28 to which the busbar 100 is connected, by a notch 126 positioned between two adjacent connection terminals 118, and by a flexible portion 128 aligned with each notch 126.

[0060] When the first conductive layer 110 is laminated onto the first insulating layer 130, the conductive elements 112 are laminated on the first insulating layer 130 and do not overlap each other. The conductive elements 112 are preferably manufactured by cutting and / or stamping a single sheet of conductive material, such as a sheet of metal, before being laminated onto the first insulating layer, which is an efficient process.

[0061] The conductive element 112 is bent during the welding process and is thin enough to accommodate positional deviations of the electrode 28, but has sufficient thickness to handle the current density when the module 10 is used in a battery. In the illustrated embodiment, the conductive element 112 has a thickness ranging from 0.25 mm to 2 mm.

[0062] As a non-limiting example, the conductive element 112 is made of a metal, such as copper, aluminum, nickel, or one of their alloys. Preferably, the surface of the first conductive layer 110 is plated with a plating material such as tin, nickel, silver, or one of their alloys, for example, to prevent oxidation.

[0063] The second conductive layer 140 extends along the main axis A100 and has two ends, each having a second electrical connector 142 and a third electrical connector 144. The second electrical connector 142 and the third electrical connector 144 are preferably connected to the respective electrodes 28 by welding, for example, by laser welding.

[0064] The second electrical connector 142 is configured to connect to the electrode 28 of the last group 30B of cell 22, which is not connected to the conductive element 112 of the first conductive layer 110.

[0065] In the example shown in Figure 3, the second electrical connector 142 is connected to the second electrode 28B of the last cell 22B, and the first electrode 28A of the last cell 22B is connected to the conductive element 112.

[0066] The third electrical connector 144 is closer to the first connector 114 than the second electrical connector 142, and the third electrical connector 144 is configured to connect to the electrodes 28 of the last group 30B of cell 22 via the remainder of the second conductive layer 140, the electrodes 28 not to the conductive elements 112 of the first conductive layer 110.

[0067] Preferably, the third connector 144 is located next to the first connector 114, as shown in the illustrated example. In other words, the first connector 114 and the third connector 144 are located on the same side of the pack 20. The second conductive layer 140 is the return circuit for the busbar 100.

[0068] A busbar 100, which forms a laminated structure including both the first conductive layer 110 and the second conductive layer 140, allows each electrode 28 of the pack 20 to be connected to the first conductive layer 110 or the second conductive layer 140 in an automated manner, preferably by laser welding, which is highly efficient. As shown in Figure 1, when the module 10 is assembled, the first connector 114 and the third connector 144 are advantageously located outside the container 12, preferably adjacent to each other. Each cell 22 of the module 10 may also be connected via the busbar 100, which is very convenient.

[0069] Optionally, the third connector 144 includes a mechanical interface 145, in the case of a stud, for mechanically connecting the first connector 114 to an external element such as a busbar (not shown).

[0070] The first insulating layer 130, sandwiched between the first conductive layer 110 and the second conductive layer 140, is provided with a notch window 134, which here has a rectangular shape and is configured to allow electrical connection between the second electrical connector 142 and the corresponding electrode 28 of the last group 30B of cell 22.

[0071] The second electrical connector 142 includes at least one connection terminal 146 configured to be welded to each electrode 28. In the first embodiment, the second electrical connector 142 includes one connection terminal 146.

[0072] As shown in Figure 5a), the connection terminal 146 of the second electrical connector 142 has a rectangular shape and is equipped with a centering hole 145. This is configured to allow visual confirmation that the second electrical connector 142 is properly aligned with the corresponding electrode 28 before the actual welding operation during the connection of the busbar 100 and the pack 20.

[0073] The second conductive layer 140 is made of a conductive material, preferably a metal having good conductivity to avoid loss of electrical energy. In non-limiting examples, the second conductive layer 140 is made of a metal, for example, copper, or aluminum, or nickel, or one of their alloys. Preferably, the surface of the second conductive layer 140 is plated with, for example, tin, or nickel, or one of their alloys, to prevent oxidation. The second conductive layer 140 is preferably made by cutting and / or pressing a metal sheet.

[0074] When module 10 is in use, the cell 22 and conductive elements 112 tend to heat up in order to store electrical energy in the cell 22 or to supply electrical energy from the cell 22. The second conductive layer 140, laminated on the first insulating layer 130, partially overlaps with the first conductive layer 110 and receives some of the thermal energy of the first conductive layer 110. In other words, the second conductive layer 140 helps to dissipate the thermal energy of the first conductive layer 110. To enhance this heat dissipation effect, the second conductive layer 140 has a surface area that overlaps with the surface area of ​​the first conductive layer 110 by more than 30%, preferably more than 50%, and preferably more than 75%.

[0075] The second conductive layer 140 has a thickness selected according to the overlap ratio of the second conductive layer 140 with respect to the first conductive layer 110, in order to cope with the current density when the module 10 in the battery is in use. According to some examples, the second conductive layer 140 has a thickness ranging from 0.25 mm to 2 mm.

[0076] The second conductive layer 140 is positioned such that it does not obstruct access to the opening 132 of the first insulating layer 110. In the first embodiment, the second conductive layer 140 includes a second opening 148 configured to allow access to the welding area 122 of each connection terminal 118. In the first embodiment of the busbar 100, the first conductive layer 110 and the second conductive layer 140 have substantially the same width, measured perpendicular to the longitudinal plane P100, and the second opening 148 has a closed profile. In the illustrated example, each second opening 148 has a circular profile and is aligned with its respective centering hole 124 along an axis perpendicular to the median plane P101.

[0077] In other words, the second opening 148 is aligned with the first opening 132 of the first insulating layer 130. The first opening 132 is preferably smaller than the second opening 148 in order to reduce the risk of short circuits through the first opening 132.

[0078] In the illustrated example, the second conductive layer 140 includes an additional notch 150 positioned between two adjacent openings 148 located on the same side of the longitudinal plane P100, each additional notch 150 extending perpendicular to the longitudinal plane P100 and configured to improve the flexibility of the second conductive layer 140 and thus the overall flexibility of the busbar 100.

[0079] As shown in Figure 2, the laminated busbar 100 further comprises a bottom insulating layer 160 that extends along the midline plane P100 of the busbar 100 and is laminated on the first conductive layer 110. In other words, the first conductive layer 110 is sandwiched between the first insulating layer 130 and the bottom insulating layer 160.

[0080] Preferably, the bottom insulating layer extends substantially over the top surface 26 of all cells 22 in the pack 20. The bottom insulating layer 160 includes a window 162 configured to allow electrical connection between each electrode 28 and the busbar 100.

[0081] Each window 162 has a contour similar to that of the electrode 28, and as a result, when the busbar 100 is placed on top of the pack 20, each electrode 28 passes through its respective window 162 and makes direct contact with its respective connector 118 or the first connector 114 or the second connector 142. In the illustrated example, each electrode 28 has a rectangular contour, and each window 162 has the same rectangular contour.

[0082] When the busbar 100 is assembled into pack 20, the bottom insulating layer 160 is placed on the top surface 26 of the cell 22, and the conductive element 112 is connected to the electrode 28. The bottom insulating layer 160 has holes 162 that allow the conductive element 112 to be electrically connected to the electrode 22 of the cell 22.

[0083] Preferably, the stacked busbar 100 further includes a monitoring circuit 170 configured to monitor the operating state of the battery 10, for example, its temperature.

[0084] In the illustrated example, the monitoring circuit 170 comprises a sensing circuit 172 having an elongated shape extending along the main axis A100, and a connector 174 connected to the end of the sensing circuit 172.

[0085] During use, the sensing circuit 172 extends across the upper side 26 of the cell 22. The sensing circuit 172 preferably comprises at least one sensor per cell 22 and is configured to monitor the state of the cell 22 located in immediate vicinity of the sensing circuit 172.

[0086] The sensing circuit 172 preferably extends along the main axis A100 from the first cell 22A to the last cell 22B and is configured to monitor the operating state of each cell 22 of the pack 20. For example, the sensor of the sensing circuit 172 is a temperature sensor, and the monitoring circuit 170 is configured to monitor the temperature of each cell 22 of the pack 20.

[0087] The laminated busbar 100 advantageously includes a top insulating layer 180 that extends along the midline plane P100 of the busbar 100 and is laminated on a second conductive layer 140. In other words, the second conductive layer 140 is sandwiched between the first insulating layer 130 and the top insulating layer 180.

[0088] Preferably, the top insulating layer 180 substantially covers the top surface 26 of all cells 22 in the pack 20. The top insulating layer 180 includes top windows 182 configured to allow access to the connection terminals 118 or the first connector 114 or the second connector 144 during welding of the busbar 100 to the electrodes 28. In the illustrated example, each top window 182 has a circle coaxial with its respective first opening 132.

[0089] In the illustrated example, the sensing circuit 172 is sandwiched between the first conductive layer 110 and the bottom conductive layer 160. For example, the sensing circuit 172 is laminated on the bottom insulating layer 160 before the bottom insulating layer 160 is laminated on the first conductive layer 110. Such an assembly process can be automated, making it efficient and low-cost.

[0090] Alternatively, the sensing circuit 172 is sandwiched between the first conductive layer 110 and the first insulating layer 130, or between the first insulating layer 130 and the second conductive layer 140, or between the second conductive layer 140 and the top insulating layer 180.

[0091] More generally, the sensing circuit 172 is laminated on any layer of the busbar 100, for example, sandwiched between two adjacent layers of the busbar 100, where these two layers comprise one of the insulating layers 160, 130, or 180 and the corresponding conductive layer 110 or conductive layer 140.

[0092] Figures 6 and 7 show a second alternative embodiment of the battery 10 according to the present invention. In this second embodiment, the same reference numerals are used for battery components that are identical or similar to those in the first embodiment. The differences between the first and second embodiments will be described in detail below.

[0093] In a second embodiment of the present invention, the cells 22 of pack 20 are arranged in groups 300, each group 300 comprising two cells 22. Pack 20 here comprises four groups 300 of cells 22.

[0094] The group 300 containing the first cell 22A is also called the first group 300A, and the group 300 containing the last cell 22B is also called the last group 300B. In other words, the first group 300A and the last group 300B are located at opposite ends of pack 20. In Figure 6, the first group 300A is located on the left and the last group 300B is located on the right, with the first group 300A separated from the last group 300B by the other two groups 300.

[0095] The battery 10 is equipped with stacked busbars 200.

[0096] The laminated busbar 200 has a laminated structure similar to that of the busbar 100 in the first embodiment, with a conductive layer sandwiched between insulating layers. However, only the conductive layer is shown in Figures 6 and 7.

[0097] The laminated busbar 200 comprises a first conductive layer 210 and a second conductive layer 240.

[0098] The first conductive layer 210 includes at least one conductive element 212, each conductive element 212 configured to electrically connect electrodes 28 belonging to two adjacent groups 300 of the cell 22, the electrodes 28 being located on the same side of the longitudinal plane P20.

[0099] Each conductive element 212 includes at least two connection terminals 118, each configured to connect to one electrode 28 of a cell 22, and a connecting member 220. Since each group 300 includes two cells 22, each conductive element 212 includes four connection terminals 118, which are connected to the connecting member 220.

[0100] More generally, cells 22 belonging to the same group 300 are electrically connected in parallel with each other, while two adjacent groups 300 connected to each other by the same conductive element 212 are connected in series with each other.

[0101] The first conductive layer 210 also includes a first electrical connector 214 configured to connect to the electrodes 28 of a first group 300A of cells that are not connected to the conductive element 212. Since each group 300 includes two cells 22, including the first group 300A, the first connector 214 is configured to connect to two electrodes 28.

[0102] The second conductive layer 240 extends along the main axis A100 and includes two ends, each equipped with a second electrical connector 242 and a third electrical connector 244.

[0103] The second electrical connector 242 is configured to connect to the electrode 28 of the last group 300B of cell 22, which is not connected to the conductive element 212 of the first conductive layer 210, while the third electrical connector 244 is closer to the first connector 214 than to the second electrical connector 242.

[0104] In the second embodiment, each group 300 of cells 22, including the last group 300B, comprises two cells 22. The second connector 242 is configured to connect to two electrodes 28 and, for this purpose, comprises two connection terminals 146.

[0105] In the second embodiment, the first conductive layer 210 and the second conductive layer 240 have substantially the same width when measured perpendicular to the longitudinal plane P100, the second opening 148 has a closed profile, in this case a circular profile, and each second opening 148 is aligned with its respective centering hole 124 along an axis perpendicular to the median plane P101.

[0106] A busbar 300 according to a third embodiment of the present invention is shown in Figure 8. The busbar 300 comprises a second conductive layer 340, while other components of the busbar 300 (not shown) are the same as those of the busbar 200 of the second embodiment.

[0107] The second conductive layer 340 extends along the main axis A100 and has two ends, each equipped with a second electrical connector 242 and a third electrical connector 244.

[0108] In the third embodiment, the second conductive layer 340 has a width measured perpendicular to the longitudinal plane P100 and is approximately equal to 70% of the width of the second conductive layer 240 in the second embodiment.

[0109] When the busbar 300 is assembled, the second conductive layer 340 overlaps with approximately 70% of the first conductive layer, so the busbar 300 is lighter than the busbar 200 of the second embodiment while maintaining good heat dissipation through the second conductive layer 340.

[0110] The second conductive layer 340 is positioned such that it does not obstruct access to the opening in the first insulating layer. In the third embodiment, the second conductive layer 340 includes a second opening 348 configured to allow access to the first conductive layer during welding operations. Due to the reduction in width of the second conductive layer 340, each second opening 148 has an open contour, in this case a semicircular contour. Two adjacent second openings 348 are separated by an additional cut 350 that is shorter than the additional cut 150 of the previous embodiment.

[0111] A busbar 400 according to a fourth embodiment of the present invention is shown in Figure 9. The busbar 400 comprises a second conductive layer 440, while other components of the busbar 400 (not shown) are the same as those of the busbar 100 of the first embodiment.

[0112] The second conductive layer 440 includes a central portion 442 to which the second electrical connector 142 and the third electrical connector 144 are attached. The second conductive layer 440 is positioned so as not to obstruct access to the opening 132 of the first insulating layer 110. More precisely, in the fourth embodiment, the second conductive layer 440 does not have an opening such as the second opening 148 or 348 of the previous embodiment, but the central portion 442 has a straight shape that is easier to manufacture.

[0113] More generally, the shape and contour of the second conductive layer can be modified according to design requirements, including straight contours or openings. The second openings 148 or 348 and additional notches 150 or 350 can be modified and / or combined and / or omitted, taking into account the constraints of electrical conductivity, thermal conductivity, and converted mass.

[0114] The features of the different embodiments and variations of module 10 and busbar 100 considered in this description can be combined.

Claims

1. A laminated busbar (100; 200; 300; 400) for interconnecting packs (20) of prismatic electric cells (22) in a module (10) from a battery, comprising: The laminated busbar (100; 200; 300; 400) has an elongated flat shape extending in a median plane (P101) along a main axis (A100), The pack (20) of electric cells (22) comprises: The electric cells (22) are configured to be arranged in a row along the main axis (A100); Each cell (22) has a top surface (26) with two electrodes (28) of opposite polarity, arranged on opposite sides of a longitudinal plane (P100) parallel to said main axis (A100) and perpendicular to said median plane (P101), said electrodes (28) of each cell (22) being arranged in said median plane (P101) and said top surface (26) of each cell (22) being oriented in the same direction; said cells (22) are arranged in at least two groups (30; 300), each group having the same number of electric cells, a first group (30A; 300A) of cells and a last group (30B; 300B) of cells (22) being arranged at opposite ends of said pack (20); Within the same group (30; 300) of cells, the electrodes (28) having the same polarity are arranged on the same side of the longitudinal plane (P100), In two adjacent groups (30; 300) of cells, the electrodes (28) having the same polarity are arranged on opposite sides of the longitudinal plane (P100), The laminated busbar (100; 200; 300; 400) is a first conductive layer (110; 210) comprising at least one conductive element (112; 212), each conductive element being configured to electrically connect said electrodes (28) of two adjacent groups (30; 300) of cells (22), said electrodes being arranged on the same side of said longitudinal plane (P100); a first insulating layer (130) laminated on the first conductive layer (110; 210); a first electrical connector (114; 214) configured to connect to electrodes (28) of a first group (30A; 300A) of cells that are not connected to the conductive elements (112; 212) of the first conductive layer; the laminated busbar (100; 200; 300; 400) further comprises a second conductive layer (140; 240; 340; 440) extending along the major axis (A100) and having two opposite ends respectively provided with a second electrical connector (142; 242) and a third electrical connector (144; 244); the second conductive layer (140; 240; 340; 440) is laminated onto a first insulating layer (130) and is electrically isolated from the first conductive layer (110; 210) by said first insulating layer, said first conductive layer being sandwiched between said first insulating layer and said electrode (28) when said laminated busbar is connected to said pack (20) of cells (22); the second electrical connector (142; 242) is configured to connect to electrodes (28) of the last group (30B; 300B) of cells (22) that are not connected to the conductive elements (112; 212) of the first conductive layer, and the third electrical connector (144; 244) is closer to the first electrical connector (114; 214) than the second electrical connector; the first insulating layer includes a cutout window (134) configured to allow electrical connection between the corresponding electrodes (28) of the last group (30B; 300B) of cells (22) and the second electrical connector; Laminated busbar (100; 200; 300; 400).

2. each said conductive element (112; 212) comprises at least two connection terminals (118) each comprising a welding area (122) configured to be welded to a respective electrode (28) of the cell (22); the first insulating layer (130) includes an opening (132) configured to allow access to the welding area of ​​each of the connection terminals; the second conductive layer (140; 240; 340; 440) is positioned such that the second conductive layer does not obstruct access to the opening (132) in the first insulating layer.

2. The laminated busbar (100; 200; 300; 400) of claim 1.

3. For each conductive element (112; 212), Two adjacent connection terminals (118; 218) are connected to each other by a connecting member (120; 220); For two adjacent connection terminals, the conductive element comprises a notch (126) disposed between the two adjacent connection terminals; Each of the notches extends perpendicular to the main axis (A100), thereby allowing each of the connection terminals to rotate relative to the coupling member along a rotation axis parallel to the main axis (A100), independently of adjacent connection terminals.

3. The laminated busbar (100; 200; 300; 400) of claim 2.

4. The connecting member (120) further comprises at least one flexible portion (128); each flexible portion extends perpendicular to the main axis (A100) and is aligned with a respective notch (126), each flexible portion separating the connecting members (120) at two adjacent connecting portions (129); each said flexible section (128) is elastically deformable so that each said link (129) rotates relative to an adjacent link along a pivot axis (A129) aligned with the corresponding flexible section; 4. The laminated busbar (100; 200; 300; 400) of claim 3.

5. Further comprising a bottom insulating layer (160); The bottom insulating layer is laminated to the first conductive layer (110; 210), the bottom insulating layer includes openings (162) configured to permit electrical connection of the conductive elements (112; 212) to corresponding electrodes (28); 5. A laminated busbar (100; 200; 300; 400) according to any one of the preceding claims.

6. Further comprising a top insulating layer (180); said top insulating layer being laminated to said second conductive layer (140; 240; 340; 440); The top insulating layer includes a top opening (182) configured to allow access to each connection terminal (118).

5. A laminated busbar (100; 200; 300; 400) according to any one of the preceding claims.

7. 5. The laminated busbar (100; 200; 300; 400) according to any one of the preceding claims, wherein the second conductive layer (140; 240; 340; 440) is made from a metal sheet.

8. 8. The laminated busbar (100; 200; 300; 400) of claim 7, wherein the second conductive layer (140; 240; 340; 440) has an area overlapping more than 30% of an area of ​​the first conductive layer (110; 210).

9. 8. The laminated busbar (100; 200; 300; 400) of claim 7, wherein the second conductive layer (140; 240; 340; 440) has a surface that overlaps more than 50% of a surface of the first conductive layer (110; 210).

10. 8. The laminated busbar (100; 200; 300; 400) of claim 7, wherein the second conductive layer (140; 240; 340; 440) has a surface that overlaps more than 75% of a surface of the first conductive layer (110; 210).

11. A module (10) for a battery comprising a pack (20) of prismatic electric cells (22), The cells (22) are interconnected by a laminated busbar (100; 200; 300; 400) according to any one of claims 1 to 4, The cells (22) are arranged in a row along the main axis (A100), Each cell (22) has a top surface (26) with two electrodes (28) of opposite polarity and arranged on opposite sides of a longitudinal plane (P100), the electrodes (28) of each cell (22) being arranged in the median plane (P101) and the top surface (26) of each cell (22) being oriented in the same direction; said cells (22) are arranged in at least two groups (30; 300) with an equal number of cells in each group, the cells of a first group (30A; 300A) and the cells of a last group (30B; 300B) being located at opposite ends of the row; Within the same group of cells (22), the electrodes (28) having the same polarity are arranged on the same side of the longitudinal plane (P100); In two adjacent groups (30; 300) of cells, the electrodes (28) having the same polarity are arranged on opposite sides of the longitudinal plane (P100); Module (10).

12. The module comprises a container (12) configured to hold the cell (22); the first connector (114) and the third connector (144) are disposed outside the container (12); A module (10) according to claim 11.

13. The module (10) of claim 12, wherein the first connector (114) and the third connector (144) are disposed adjacent to one another.

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