Cell connection assembly

Abstract

The present disclosure relates to cell connection assemblies for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells. The disclosure also relates to a method of electrically coupling a cell connection assembly with positive and negative terminals of an arrangement of a plurality of battery cells, and a battery-terminal-connecting layer for forming part of a cell connection assembly.

Description

[0001] CELL CONNECTION ASSEMBLY

[0002] Field

[0003] The present disclosure relates to cell connection assemblies for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells. The disclosure also relates to a method of electrically coupling a cell connection assembly with positive and negative terminals of an arrangement of a plurality of battery cells, and a battery-terminal-connecting layer for forming part of a cell connection assembly.

[0004] Background

[0005] A plurality of battery cells, such as cylindrical battery cells, are typically arranged together and then electrically connected to form a battery module assembly. Accurate and efficient coupling of the plurality of battery cells during assembly is important.

[0006] Summary

[0007] According to a first aspect of the present disclosure there is provided a cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane for coupling the battery cells via connection to a positive or a negative terminal; a second battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a second plane for coupling the battery cells via connection to a positive or negative terminal different from the positive or negative terminals to which the first battery-terminal-connecting layer is configured for connection; a first insulation layer comprising an electrical insulator, arranged between the first battery-terminal-connecting layer and the second batteryterminal-connecting layer, in a third plane; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement; wherein the current collector of the first battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window, the flexible projection configured to be pressed out of the first plane to secure it to the respective terminal; and wherein the current collector of the second battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window, the flexible projection configured to be pressed out of the second plane to secure it to the respective terminal.

[0008] The cell connection assembly may advantageously provide electrical connection to each battery cell of the plurality of battery cells via a single, compact laminated structure arranged adjacent a single side of the plurality of battery cells.

[0009] In one or more embodiments, the tabs are each configured to flex when pressed against a respective terminal and are configured for laser welding thereto through the window. Such a device allows for assembly of a battery module comprising an arrangement of a plurality of battery cells wherein electrical connection of the battery cells, via the cell connection assembly, is one of the final assembly steps. This reduces the likelihood of cells short circuiting during the assembly process.

[0010] In one or more embodiments, the laminated structure comprises one or both of: a second insulation layer comprising an electrical insulator arranged adjacent the first battery-terminal-connecting layer and opposed the first insulation layer; and a third insulation layer comprising an electrical insulator arranged adjacent the second battery-terminal-connecting layer and opposed the first insulation layer.

[0011] The first and second battery-terminal-connecting layers may therefore be sandwiched between the second and third insulation layers, as well as being separated by the first insulation layer. Accordingly, the first and second battery-terminal-connecting layers are protected from inadvertent electrically conductive contact with one another and inadvertent electrically conductive contact with other components, such as battery cells, during assembly of a battery module.

[0012] In one or more embodiments, one of the first and second battery-terminalconnecting layers comprises a first main connector that extends out from the laminated structure to provide a negative terminal for the plurality of battery cells that are electrically connected by the cell connection assembly. Further, one of the first and second battery-terminal-connecting layers may comprise a second main connector that extends out from the laminated structure to provide the positive terminal for the plurality of battery cells that are electrically connected by the cell connection assembly.

[0013] In one or more examples, the first battery-terminal-connecting layer comprises the first main connector and the second main connector, thereby providing both the main connectors for the negative and the positive terminals for the plurality of battery cells. In one or more other examples, the second batteryterminal-connecting layer comprises both the first main connector and the second main connector, thereby providing both the main connectors for the negative and the positive terminals for the plurality of battery cells. In one or more further examples, one of the first battery-terminal-connecting layer and the second battery-terminal-connecting layer comprises the first main connector providing the negative terminal for the plurality of battery cells, and the other of the first battery-terminal-connecting layer and the second batteryterminal-connecting layer comprises the second main connector providing the positive terminal for the plurality of battery cells. In one or more examples, the first main connector includes a crimp for accommodating movement of the first main connector relative to a remainder of the cell connection assembly. In one or more examples, the second main connector includes a crimp for accommodating movement of the second main connector relative to a remainder of the cell connection assembly.

[0014] The crimp may advantageously enable the cell connection assembly to accommodate movement of the plurality of battery cells relative to the battery module.

[0015] In one or more embodiments, the first main connector and the second main connector extend from a common edge of the laminated structure of the cell connection assembly. Thus, the laminated structure may include a plurality of edges and the main connectors may extend from the same one edge.

[0016] In one or more embodiments, the first main connector and the second main connector extend from the common edge in a first direction for securement to further parts and at least a subset of the plurality of tabs are configured to project into their respective windows at an angle greater than 30 degrees from the first direction. In some embodiments, the subset of the plurality of tabs are configured to project into their respective windows at an angle of between 30 and 150 degrees to the first direction; preferably between 40 and 140 degrees; more preferably between 45 and 135 degrees.

[0017] By virtue of the tabs projecting at an angle to the first direction, each tab may advantageously accommodate movement of an individual battery cell relative to the cell connection assembly.

[0018] In one or more embodiments, the at least first and second battery-terminalconnecting layers provide for electrical connection to all terminals of the plurality of battery cells at a single side of the arrangement of the plurality of battery cells.

[0019] In one or more embodiments, the current collector of the first battery-terminalconnecting layer comprises a first row part and a separate, second row part arranged side-by-side in the first plane, wherein the first row part and the second row part are connected at a first end of the first battery-terminalconnecting layer by a first connector layer, the first connector layer comprising an electrically conductive, substantially U-shaped member extending substantially perpendicular to the first plane.

[0020] Additionally or alternatively, the current collector of the second batteryterminal-connecting layer comprises a first row part and a separate, second row part arranged side-by-side in the second plane, wherein the first row part and the second row part are connected at a first end of the second batteryterminal-connecting layer by a second connector layer, the second connector layer comprising an electrically conductive, substantially U-shaped member extending substantially perpendicular to the second plane.

[0021] In one or more embodiments, one or more of the first row part of the first battery-terminal-connecting layer, the second row part of the first batteryterminal-connecting layer, and the first connector layer, include cut-outs or notches to increase the electrical resistance in a region to control current density when current flows between the first row and the second row through the first connector layer.

[0022] Additionally or alternatively, one or more of the first row part of the second battery-terminal-connecting layer, the second row part of the second batteryterminal-connecting layer, and the second connector layer, include one or more cut-outs or notches to increase the electrical resistance in a region to control current density when current flows between the first row and the second row through the second connector layer.

[0023] The first and / or second connector layer may be shaped to reduce ohmic losses and maintain even distribution of the electrical current as it is turned around from the first row part to the second row part. For example, the U-shaped member may be configured such that, throughout the 180° turn, the width of electrically conductive material remains similar to the width of the electrically conductive material in the first and second row parts. It is to be understood that any shape which maintains a minimum width of electrically conductive material similar to that which is present in the first and second row parts should be considered as substantially U-shaped. For example, the substantially U- shaped member may have a substantially semi-circular shape or may comprise one or more straight edges and be considered substantially U-shaped.

[0024] In one or more embodiments, the plurality of tabs of the first battery-terminalconnecting layer and the plurality of tabs of the second battery-terminalconnecting layer are one or both of a positive tab type and a negative tab type, wherein the positive tab type is configured to couple to the positive terminal of the plurality of battery cells and the negative tab type is configured to couple to the negative terminal of the plurality of battery cell.

[0025] In one or more embodiments, the positive tab type comprises an elongate arm projecting into the window and a head at the distal end of the elongate arm to electrically couple to the positive terminal.

[0026] Each head may be advantageously shaped and sized to align with the positive terminal of a respective battery cell.

[0027] In one or more embodiments, the negative tab type comprises an arcuate finger projecting into the window to electrically couple to the negative terminal, wherein the plurality of battery cells comprise cylindrical cells and the negative terminal comprise a ring-shaped edge of a can of said cylindrical cells.

[0028] Each arcuate finger may be advantageously shaped and sized to align with part of the negative terminal of a respective battery cell.

[0029] In one or more embodiments, the arcuate finger includes one or more tapers along its length configured to reveal parts of the ring-shaped edge of the can when viewed through the windows.

[0030] Each arcuate finger may be advantageously shaped and sized to provide a suitably large weld site for connection to the negative terminal of a respective battery cell while also providing good visibility of the battery cell through the respective window. In one or more embodiments, the plurality of battery cells comprises cylindrical cells and each of the windows is sized and arranged to reveal at least part of a circular edge of the negative terminal of said cylindrical cells.

[0031] Each window may be advantageously shaped and sized to provide good visibility of the battery cell through the respective window while not being so large that the structural strength of the cell connection assembly is unduly weakened.

[0032] In one or more embodiments, the current collector of the first battery-terminalconnecting layer comprises a plurality of separate sub-collectors in the first plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of a first parallel subset of battery cells of the plurality of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a second parallel subset of battery cells. Furthermore, the current collector of the second battery-terminal-connecting layer may comprise a plurality of separate sub-collectors in the second plane, wherein at least one of the subcollectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of said second parallel subset of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a third parallel subset of battery cells.

[0033] The cell connection assembly therefore advantageously electrically connects the plurality of battery cells in a hybrid configuration combining both series and parallel connections. This enables much greater control over current density across the first and second battery-terminal-connecting layers.

[0034] According to a second aspect of the present disclosure there is provided a method of electrically coupling a cell connection assembly with positive and negative terminals of an arrangement of a plurality of battery cells, the method comprising: receiving the arrangement of the plurality of battery cells; receiving a cell connection assembly according to the first aspect of the invention and aligning the cell connection assembly relative to the arrangement of the plurality of battery cells; applying a pressing apparatus through the plurality of windows to press the plurality of tabs of the first battery-terminal-connecting layer out of the first plane and the plurality of tabs of the second battery-terminal-connecting layer out of the second plane and to press the tabs of the first and second battery-terminal-connecting layers against respective positive and negative terminals of the plurality of battery cells; and actuating a laser welder to weld the tabs to the respective positive and negative terminals.

[0035] The features and advantages of the first aspect of the invention and its embodiments apply mutatis mutandis to the second aspect of the invention and its embodiments. Thus, an arrangement of cylindrical battery cells that may present their positive and negative terminals at a single side of the arrangement are electrically coupled in an effective manner by the cell connection assembly.

[0036] Accordingly, by virtue of using a cell connection assembly according to the first aspect of the invention, the steps required to provide an electrical connection to both terminals of each battery cell may be performed from a single direction.

[0037] In one or more embodiments, the pressing apparatus and the laser welder may be integrated as a single device, accordingly, the pressing and welding steps may be performed as a single action.

[0038] In one or more embodiments, the method includes actuating the laser welder to align itself for performing said weld based on one or more captured images of each of the battery cells as viewed through the windows.

[0039] In one or more embodiments, said plurality of battery cells comprises cylindrical cells and the step of actuating the laser welder to align itself comprises aligning based on one or more captured images of each of the battery cells as viewed through the windows and automatic identification of at least part of a circular edge of an end of said cylindrical cells.

[0040] Therefore, each weld site may be determined according to the specific positioning of each individual battery cell, thereby compensating for any manufacturing tolerances having a bearing on the specific positioning of an individual cell and its terminals.

[0041] In one or more embodiments, the method further comprises a step of assembling the arrangement of a plurality of battery cells and the cell connection assembly electrically coupled thereto wit into a battery system. Optionally, said battery system is included in a vehicle.

[0042] According to a third aspect of the present disclosure there is provided a batteryterminal-connecting layer for forming part of a cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the battery-terminal-connecting layer comprising: an electrically conductive current collector arranged in a first plane for coupling to one of the positive and negative terminals or both positive and negative of the battery cells, the current collector comprising a first row part and a separate, second row part arranged side-by-side in the first plane; and an electrically conductive connector layer connecting the first row part and the second row part at a first end of the first battery-terminal-connecting layer, the connector layer extending substantially perpendicular to the first plane.

[0043] The features and advantages of the first and second aspects of the invention and their embodiments apply mutatis mutandis to the third aspect of the invention and its embodiments.

[0044] In one or more embodiments, the connector layer comprises a substantially U- shaped member.

[0045] In one or more embodiments, one or more of the first row part, the second row part and the connector layer, include cut-outs or notches to increase the electrical resistance in a region to control current density when current flows between the first row and the second row through the connector layer.

[0046] According to a fourth aspect of the present disclosure there is provided a cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane for coupling to one of the positive and negative terminals or both positive and negative terminals of the battery cells, and a first main connector that extends out from the laminated structure to provide a positive terminal for the plurality of battery cells that are electrically connected by the cell connection assembly; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement; wherein the current collector of the first battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window; and wherein the first main connector extends from the laminated structure in a first direction for securement to further parts and at least a subset of the plurality of tabs are configured to project into their respective windows at an angle greater than 30 degrees from the first direction.

[0047] The features and advantages of the preceding aspects of the invention and their embodiments apply mutatis mutandis to the fourth aspect of the invention and its embodiments.

[0048] In one or more embodiments, the subset of the plurality of tabs are configured to project into their respective windows at an angle of between 30 and 150 degrees to the first direction. In some embodiments, the subset of the plurality of tabs are configured to project into their respective windows at an angle of between 40 and 140 degrees; preferably between 45 and 135 degrees.

[0049] According to a fifth aspect of the present disclosure there is provided a cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane for coupling to one of the positive and negative terminals or both positive and negative terminals of the battery cells, and a first main connector that extends out from the laminated structure to provide a positive terminal for the plurality of battery cells that are electrically connected by the cell connection assembly; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement; wherein the current collector of the first battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window, the flexible projection configured to be pressed out of the first plane to secure it to the respective terminal; and wherein the plurality of battery cells comprises cylindrical cells and each of the windows is sized and arranged to reveal at least part of a circular edge of an end of said cylindrical cells.

[0050] The features and advantages of the preceding aspects of the invention and their embodiments apply mutatis mutandis to the fifth aspect of the invention and its embodiments.

[0051] In one or more embodiments, the plurality of tabs of the first battery-terminalconnecting layer and the plurality of tabs of the second battery-terminalconnecting layer are one or both of a positive tab type and a negative tab type, wherein the positive tab type is configured to couple to the positive terminal of the plurality of battery cells and the negative tab type is configured to couple to the negative terminal of the plurality of battery cell.

[0052] In one or more embodiments, the negative tab type comprises an arcuate finger extending from either the respective battery-terminal-connecting layer into the window to electrically couple to the negative terminal, wherein the plurality of battery cells comprise cylindrical cells and the negative terminal comprise a ring-shaped edge of a can of said cylindrical cells.

[0053] In one or more embodiments, the arcuate finger includes one or more tapers along its length configured to reveal parts of the ring-shaped edge of the can when viewed through the windows.

[0054] According to a sixth aspect of the present disclosure there is provided a cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane, the current collector comprising a plurality of separate sub-collectors in the first plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of a first parallel subset of battery cells of the plurality of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a second parallel subset of battery cells; a second battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a second plane, the current collector comprising a plurality of separate sub-collectors in the second plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of the second parallel subset of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of third parallel subset of battery cells; a first insulation layer comprising an electrical insulator, arranged between the first battery-terminal-connecting layer and the second batteryterminal-connecting layer in a third plane; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement and enable access to respectively aligned tabs of the first and second battery-terminal-connecting layers.

[0055] The features and advantages of the preceding aspects of the invention and their embodiments apply mutatis mutandis to the sixth aspect of the invention and its embodiments.

[0056] A seventh aspect of the disclosure may comprise a vehicle including a battery system comprising a cell connection assembly described herein. The vehicle may comprise a battery electric vehicle and the battery system may be configured to provide motive power.

[0057] An eighth aspect of the disclosure may comprise a battery system comprising a cell connection assembly described herein, wherein the battery system comprises a battery energy storage system, such as grid-connected battery energy storage system. In other examples, the battery system is housed in a vehicle accessory, such as part of a trailer, roof-box or the like.

[0058] While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that other embodiments, beyond the particular embodiments described, are possible as well. All modifications, equivalents, and alternative embodiments falling within the scope of the appended claims are covered as well.

[0059] The above discussion is not intended to represent every example embodiment or every implementation within the scope of the current or future claim sets. The figures and Detailed Description that follow also exemplify various example embodiments. Various example embodiments may be more completely understood in consideration of the following Detailed Description in connection with the accompanying drawings. Brief of the

[0060] One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which:

[0061] Figure 1 shows an example embodiment of a cell connection assembly;

[0062] Figure 2 shows the layers forming the cell connection assembly of Figure 1;

[0063] Figures 3 and 4 show close-up views of layers shown in Figure 2;

[0064] Figures 5 and 6 show close-up views of the cell connection assembly of Figure 1 when in use;

[0065] Figure 7 shows a close-up view of a battery-terminal-connecting layer forming part of the cell connection assembly of Figure 1;

[0066] Figure 8 shows the cell connection assembly of Figure 1 and the electrical circuit it provides;

[0067] Figure 9 show a further close-up view of the cell connection assembly of Figure 1 when in use;

[0068] Figure 10 shows first and second battery-terminal-connecting layers forming part of the cell connection assembly of Figure 1;

[0069] Figure 11 shows an example embodiment of a battery module;

[0070] Figure 12 shows an example of battery cells and their movement in the battery module of Figure 11;

[0071] Figure 13 shows a further close-up view of a battery-terminal-connecting layer forming part of the cell connection assembly of Figure 1;

[0072] Figure 14 show a further close-up view of the cell connection assembly of Figure 1 when in use, particularly highlighting possible movement of battery cells;

[0073] Figure 15 shows an example embodiment of a method of electrically coupling a cell connection assembly with positive and negative terminals of an arrangement of a plurality of battery cells; and

[0074] Figure 16 show a further close-up view of the cell connection assembly of Figure 1 when in use, particularly a single window of the cell connection assembly. Detailed Description

[0075] A battery assembly typically comprises an arrangement of a plurality of cylindrical battery cells. For example, a battery assembly may comprise tens or hundreds of cylindrical battery cells arranged together.

[0076] Cylindrical battery cells, as will be familiar to those skilled in the art, comprise a curved side wall, forming a tubular casing, separating two ends. At a first end is a top cap that forms the positive terminal of the cylindrical battery cell. The negative terminal is formed by the tubular casing. At the first end, the tubular casing is typically crimped to form a shoulder to the battery cell wherein the shoulder is separated from the positive terminal by an insulating gasket. Accordingly, both the positive and the negative terminal are accessible at a single end of the battery cell.

[0077] In a battery assembly, the cylindrical cells are typically stacked together side- by-side, such that their curved side walls are adjacent one another. The first end of each of the plurality of battery cells may therefore lie in a plane providing for electrical connection of the cells.

[0078] To collect energy from the battery assembly, a means of electrical connecting to each of the battery cells is required. Due to the number of battery cells in a battery assembly, it is inefficient to require separate parts to connect each battery cell.

[0079] It may be desirable to electrically connect the battery cells together in different configurations, such as series or parallel configuration or as groups of parallel connected cells. Other factors, such as thermal management, balancing discharge, or managing the degradation of cells at particular positions in the arrangement, may be important when deciding how to electrically connect the battery cells. Accordingly, having an effective and adaptable way of electrically coupling an arrangement of battery cells may be advantageous.

[0080] It will be appreciated that effective connection of the battery cells presents a challenge. The embodiments described herein illustrate how electrical connection of the plurality of battery cells may be provided.

[0081] Figures 1 and 2 show a cell connection assembly 100, for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells. The cell connection assembly 100 comprises a laminated structure of a plurality of layers including first and second battery-terminal-connecting layers (or "BTC layers") 102, 104 and a first insulation layer 106.

[0082] The first BTC layer 102 comprises an electrically conductive current collector arranged in a first plane and the second BTC layer 104 comprises an electrically conductive current collector arranged in a second plane spaced from and substantially parallel to the first plane. The first insulation layer 106 is arranged between the first and second BTC layers 102, 104 in a third plane, generally parallel to both the first and second planes.

[0083] In this embodiment, the plurality of layers forming the cell connection assembly 100 also comprises second and third insulation layers 108, 110 arranged such that the first BTC layer 102 is sandwiched between first and second insulation layers 106, 108, and the second BTC layer 104 is sandwiched between second and third insulation layers 108, 110.

[0084] The laminated structure further includes a plurality of windows 112, each of which provides an opening in the laminated structure. In the present example, the windows 112 provide openings through the laminated structure from one planar side to the other planar side in a direction perpendicular to the planes.

[0085] Figures 3 and 4 show the first BTC layer 102, second BTC layer 104 and first insulation layer 106 in more detail.

[0086] The electrically conductive current collector of each of the first and second BTC layers 102, 104 includes a plurality of tabs 114, each tab 114 comprising a flexible projection 116 configured to project into one of the plurality of windows 112. Thus, each window 112 provides an opening that is configured to align with a single one of the battery cells of the arrangement. However, in other examples, one or more of the windows may be sized and configured to align with a plurality of battery cells. Accordingly, the current collector may be configured to provide a number of tabs to project into the window corresponding to the total number of terminals of the battery cells aligned with the window.

[0087] As shown in Figures 5 and 6, each window 112 is configured to, in use, align with a battery cell 120 from the plurality of battery cells when the cell connection assembly 100 is placed adjacent an arrangement of a plurality of battery cells 120.

[0088] The first BTC layer 102 is configured for coupling battery cells 120 via connection to a positive terminal 122 or a negative terminal 124 of a respective battery cell. More specifically, each tab 114 is configured to electrically couple to a terminal 122, 124 of the one or more battery cells aligned with the associated window 112, wherein the flexible projection 116 is configured to be pressed out of the first plane to secure it to the respective terminal 122, 124.

[0089] Similarly, the second BTC layer 104 is configured for coupling battery cells 120 via connection to a positive terminal 122 or a negative terminal 124 of a respective battery cell. Again, each tab 114 is configured to electrically couple to a terminal 122, 124 of the one or more battery cells aligned with the associated window 112. However, in this case, the flexible projection 116 is configured to be pressed out of the second plane to secure it to the respective terminal 122, 124.

[0090] Each flexible projections 116 may be secured to its respective terminal 122, 124 by means of laser welding through the respective window 112. Once the flexible projections 112 are secured to the respective terminals, the first and second BTC layers 102, 104 provide for electrical connection to all terminals 122, 124 of the plurality of battery cells 120 at a single side of the arrangement of the plurality of battery cells 120. In other words, there is no requirement for further electrical connection components positioned at an opposite side of the arrangement of the plurality of battery cells 120 (i.e. the opposite side where the other ends of the cylindrical cells are located).

[0091] In this embodiment, the plurality of tabs 114 of the first BTC layer 102 and the plurality of tabs 114 of the second BTC layer 104 include both a positive tab type 114a and a negative tab type 114b. The positive tab type 114a is configured to couple to the positive terminal 122 of a respective battery cell 120 and the negative tab type 114b is configured to couple to the negative terminal 124 of a respective battery cell 120.

[0092] Figure 7 shows part of the first BTC layer 102 and particularly shows the positive tab type 114a and a negative tab type 114b more clearly. The positive tab type 114a comprises an elongate arm 117 configured to project into the window 112 and a head 118 at the distal end of the elongate arm 117 to electrically couple to the positive terminal 122.

[0093] The negative tab type 114b comprises an arcuate finger 119 projecting into the window 112 to electrically couple to the negative terminal 124. The negative terminal 124 of the cylindrical battery cells 120 is formed by a ringshaped edge of a can of said cylindrical cells 120. The arcuate finger 119 is therefore configured to extend along an arc of the ring-shaped edge of the can.

[0094] In the present example the current collector of each of the first and second BTC layers 102, 104 include tabs that are configured for coupling a positive terminal of at least one battery cell of the arrangement with a negative terminal of at least one different battery cell of the arrangement. Thus, a current collector may have tabs of positive type configured to couple to the positive terminals of a first group of battery cells and tabs of negative type configured to couple to the negative terminals of a second, mutually exclusive, group of battery cells of the arrangement. However, in other examples, the current collector of the first BTC layer may be configured to couple to one of the positive and negative terminals of the battery cells of the arrangement and the current collector of the second BTC layer may be configured to couple to the other of the positive and negative terminals of the battery cells of the arrangement, possibly providing an entirely parallel electrical coupling of the battery cells of the arrangement.

[0095] Referring now to Figures 8, 9 and 10, the cell connection assembly 100 is configured such that current collector of the first and second BTC layers 102, 104 comprises a first row part 130 and a separate, second row part 132 arranged side-by-side in the respective planes. The first and second row parts 130, 132 are more clearly visible in Figure 10. Thus, the battery cells of the arrangement may be designated as being for electrical coupling by the first row part or designated as for electrical coupling by the second row part. The battery cells may be arranged in two rows side-by-side with some delineation therebetween or the designation may be notional.

[0096] In the first BTC layer 102, the first row part 130 and the second row part 132 are connected at a first end of the first battery-terminal-connecting layer by a connector layer 134 comprising an electrically conductive, substantially 11- shaped member extending substantially perpendicular to the first plane. Thus, the first and second row parts 130, 132 may be electrically isolated from one another without electrical connections crossing a dividing line between the side-by-side arranged row parts and wherein the row parts are electrically coupled at the first end by the connector layer 134.

[0097] By provision of the connector layer 134 as a layer or sheet extending substantially perpendicular to the plane in which the BTC layers reside enables the connecting layer 134 to sit along a side of the arrangement of battery cells parallel to the cylindrical side walls of the battery cells that form the arrangement. This has been found to be space efficient, and relatively easy to manufacture and assemble without the need for busbars and the like to couple the row parts 130, 132.

[0098] The connector layer 134 may be shaped to reduce ohmic losses and maintain even distribution of the electrical current as it is turned around from the first row part 130 to the second row part 132. For example, the U-shaped member may be configured such that, throughout the 180° turn, the width of electrically conductive material remains similar to the width of the electrically conductive material in the first and second row parts 130, 132.

[0099] In this particular embodiment, the shape is substantially semi-circular, similarly to the turn of a running track, as this minimises the amount of material required to provide the desired width available for electrical conduction. However, it is to be understood that any shape which maintains a minimum width of electrically conductive material similar to that which is present in the first and second row parts 130, 132 (or, rather than width, similar current handling capacity) should be considered as substantially 11- shaped. For example, the substantially U-shaped member may comprise one or more straight edges and still be considered substantially U-shaped.

[0100] The connector layer 134 extends substantially perpendicular to the first plane to reduce the footprint of the overall battery assembly. The connector layer 134 is also protected by virtue of extending alongside the cylindrical battery cells 120 rather than projecting outwardly from them. As shown in Figure 2, the first, second and third insulation layers 102, 104, 106 each extend parallel to the connector layer 134, both to protect it and electrically insulate it from the battery cells 120.

[0101] In Figure 9, the second row part 132 of the first BTC layer 102 includes a cutout 136. The cut-out 136 is configured to increase electrical resistance in a region to control current density across the electrical conductors of the first and second BTC layers 102, 104, particularly as electrical current flows between the first row and the second row through the connector layer 134.

[0102] In this embodiment, the cut-out 136 is located in a region of the second row part 132 closest to both the connector layer 134 and the first row part 130 to increase electrical resistance in and around the nearby tabs, thereby preventing high current density in that region. Thus, the cut-out(s) or other current-density controlling features may be provided in a region including the shortest current path or path of least electrical resistance between the first and second row parts 130, 132. It will be appreciated that the inclusion of the cutout 136 increases the localised electrical resistance and mitigates high current densities that may be observed in that region due to it representing the path of least resistance for electrical current leaving the connector layer. This may control heat build-up during use.

[0103] In other embodiments, the cut-out may be moved and / or additional cut-outs or notches may be added into the first and second BTC layers 102, 104 to manage current density. Other current density management strategies may also be employed. For example, the current-density controlling features may include the thickness of conductive material, which may be increased or reduced in certain regions to adjust electrical resistance in that region and thereby control the current density when the cell connection assembly is in use.

[0104] In some embodiments, the first and second BTC layers 102, 104 may be configured to achieve a predetermined threshold of current contribution equality across all individual battery cells 120.

[0105] For example, the predetermined threshold may be a maximum current contribution delta of ±5% between individual cells 120, preferably ±2%, more preferably ±1%. The cell connection assembly 100 is configured for use in a battery assembly wherein each battery cell is intended to contribute 10 A. Accordingly, the threshold limits for an individual cell 120 may be from 9.5 A to 10.5 A, preferably from 9.8 A to 10.2 A, more preferable from 9.9 A to 10.1 A.

[0106] In some embodiments, the current collectors of the first and second BTC layers may each be provided as single continuous layers of electrically conductive material. In such embodiments, one of the first and second BTC layers may include the positive tabs for the entire plurality of battery cells while the other of the first and second BTC layers includes the negative tabs for the entire plurality of battery cells. In other words, the plurality of battery cells may be electrically connected in an entirely parallel configuration.

[0107] In other embodiments, the current collector of the first battery-terminalconnecting layer may comprise a plurality of separate sub-collectors in the first plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of a first parallel subset of battery cells of the plurality of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a second parallel subset of battery cells, wherein the battery cells of the first and second subsets are mutually exclusive. Similarly, the current collector of the second battery-terminal-connecting layer may comprise a plurality of separate sub-collectors in the second plane, wherein at least one of the subcollectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of said second parallel subset of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a third parallel subset of battery cells, wherein the battery cells of the second and third subsets are mutually exclusive. The cell connection assembly 100 discussed with respect to Figures 1 to 9 is one such embodiment.

[0108] Figure 10 shows the first and second BTC layers 102, 104 arranged side by side. The current collectors of the first and second BTC layers 102, 104 comprise a plurality of separate sub-collectors 126. In use, the sub-collectors 126 of the first BTC-layer 102 would each be located in the first plane while the sub-collectors 126 of the second BTC-layer 104 would each be located in the second plane.

[0109] In this embodiment, there are fifteen sub-collectors in total. A first subcollector 126a, which forms part of the first BTC layer 102, comprises a plurality of positive tabs 114a for electrically coupling to the positive terminals of a first parallel subset 128a of the plurality of battery cells. More specifically, there are twelve positive tabs 114a and the first parallel subset 128a would include twelve battery cells. The battery cells belonging to the first parallel subset 128a are not shown in Figure 10 but their location, when the first BTC layer 102 is in use, is indicated by a box drawn with a broken line.

[0110] The first sub-collector 126a also comprises a plurality of negative tabs 114b for electrically coupling to the negative terminals of a second parallel subset 128b of the plurality of battery cells. The battery cells belonging to the second parallel subset 128b are also not shown in Figure 10 but their location, when the first BTC layer 102 is in use, is indicated by a further box drawn with a broken line.

[0111] A second sub-collector 126b, which forms part of the second BTC layer 104, comprises a plurality of positive tabs 114a for electrically coupling to the positive terminals of the second parallel subset 128b of the plurality of battery cells. The battery cells belonging to the second parallel subset 128b are not shown in relation to the second BTC layer either but their location, when the second BTC layer 104 is in use, is indicated by a further box drawn with a broken line.

[0112] The second sub-collector 126b also comprises a plurality of negative tabs 114b for electrically coupling to the negative terminals of a third parallel subset 128c of the plurality of battery cells. The battery cells belonging to the third parallel subset 128c are not shown in Figure 10 but their location, when the second BTC layer 104 is in use, is indicated by a further box drawn with a broken line.

[0113] Thus, the first sub-collector 126a and the second sub-collector 126b, when arranged in their respective layers are interleaved such that the negative tabs 114b for electrically coupling to the negative terminals of the second parallel subset 128b of the plurality of battery cells are configured to project into the same respective windows and therefore couple to the same battery cells as the positive tabs 114a for electrically coupling to the positive terminals of the second parallel subset 128b of the plurality of battery cells.

[0114] In summary, each parallel subset of the plurality of battery cells comprises a group of battery cells that are electrically connected to one another in a parallel configuration via positive tabs 114a in one of the first and second BTC layers 102, 104 and negative tabs in the other of the first and second BTC layers 102, 104. Further, in this example, each parallel subset is also electrically connected to an adjacent parallel subset in a series configuration via a sub-connector belonging to one of the first and second BTC layers 102, 104. It will be appreciated that a sub-connector including a main connector 140, 142 (described below) may be coupled differently. In the embodiment shown in Figure 10, there would be a total of fourteen parallel subsets (each consisting of twelve battery cells) connected to one another, in series, such that electrical current is able to flow along a U-shaped circuit through the current connecting assembly 100, as demonstrated by the arrows in Figure 8.

[0115] In other embodiments, a current connecting assembly may be configured to electrically connect more or fewer battery cells to one another in parallel within each parallel subset. Similarly, a current connecting assembly may be configured to electrically connect more or fewer parallel subsets to one another in series. In further embodiments, a current connecting assembly may be configured with more than two BTC layers. Such embodiments may facilitate more intricate hybrid combinations of parallel and series electrical connection and / or more intricate electrical conduction paths through the cell connection assembly.

[0116] Figure 10 also shows that the second BTC layer 104 comprises the first main connector 140 that extends out from the laminated structure (see Figures 1 and 3) to provide a negative terminal for the plurality of battery cells 120 that are electrically connected by the cell connection assembly 100. The second BTC layer 104 also comprises the second main connector 142 that extends out from the laminated structure (see Figures 1 and 3) to provide the positive terminal for the plurality of battery cells 120 that are electrically connected by the cell connection assembly 100. It will be appreciated that in such an example, the main connectors 140, 142 project from a different sub-connector that resides in the same, second BTC layer 104.

[0117] In this embodiment, the first main connector 140 and the second main connector 142 extend from a common edge of the laminated structure of the cell connection assembly 100. This may facilitate more convenient electrical connection to the plurality of battery cells 120.

[0118] Both the first main connector 140 and the second main connector 142 include a crimp 144 (see Figure 3) for accommodating movement of the first and second main connectors 140, 142 (and anything attached to them) relative to a remainder of the cell connection assembly 100. The crimp 144 reduces fatigue, and the likelihood of eventual failure, in the first and second main connectors 140, 142.

[0119] In other embodiments, the crimp 144 may be replaced by a different resiliently compressible and / or extendible member, such as a spring.

[0120] In some embodiments of the invention, the plurality of battery cells 120 connected to the cell connection assembly 100 are arranged within a battery module 150, as shown in Figure 11. The battery module 150 may be included in a battery system. The battery system may be included in a vehicle, such as a battery electric vehicle, and may be configured to provide motive power. Alternatively, the battery system may comprise a battery energy storage system, such as a grid-connected battery energy storage system. In other examples, the battery system may be housed in a vehicle accessory, such as part of a trailer, roof-box or the like.

[0121] Although the crimp 144 beneficially reduces fatigue in the first and second main connectors 140, 142, it has an additional effect of enabling movement of the cell connection assembly 100 relative to the rest of the battery module 150.

[0122] With reference to Figure 12, the battery cells 120 may be held in place within the battery module 150 by cell holders 152, each of which is configured to receive a lower end or portion of a respective battery cell 120. Thus, the holder may be configured to cup an end of a respective battery cell.

[0123] Meanwhile, the top end of each battery cell is connected to the cell connection assembly 100 via the terminals. Therefore, as the battery module 150 begins to vibrate in use (due to vibrations in a vehicle, for example) it is possible that the battery cells 120 may begin to move back and forth (or wobble) in the direction that the first and second main connectors 140, 142 extend from the common edge of the laminated structure of the cell connection assembly. This direction is indicated as the Y-direction in Figures 11 and 12. Figure 12 shows the manner in which individual battery cells may wobble within the battery module 150. The degree of movement is exaggerated for demonstration.

[0124] This movement of the battery cells 120 could potentially be problematic in that it could cause fatigue of the tabs 114a, 114b.

[0125] Referring now to Figures 13 and 14, both the positive and negative tabs 114a, 114b project into their respective windows at an angle greater than 30 degrees from the Y-direction. Specifically, the positive tabs project into their respective windows at an angle of about 45° to the Y-direction, while the negative tabs project into their respective windows substantially perpendicular to the Y- direction. The orientation of the tabs 114a, 114b means that they are flexible to accommodate movement of the top portions of the battery cells 120 in the Y-direction, reducing fatigue and the likelihood of the tabs 114a, 114b breaking due to vibration of the battery module 150.

[0126] Figure 15 shows a method 200 of electrically coupling a cell connection assembly 100 with positive and negative terminals 122, 124 of an arrangement of a plurality of battery cells 120.

[0127] The method comprises:

[0128] 202) receiving the arrangement of the plurality of battery cells 120;

[0129] 204) receiving the cell connection assembly 100 and aligning it relative to the arrangement of the plurality of battery cells 120;

[0130] 206) applying a pressing apparatus through the plurality of windows 112 to press the plurality of tabs 114 of the first BTC layer 102 out of the first plane and the plurality of tabs 114 of the second BTC layer 104 out of the second plane and to press the tabs 114 of the first and second BTC layers 102, 104 against respective positive and negative terminals 122, 124 of the plurality of battery cells 120; and

[0131] 208) actuating a laser welder to weld the tabs 114 to the respective positive and negative terminals 122, 124. In Figure 16, a single window 112 and associated components are shown in detail.

[0132] In this embodiment, the pressing apparatus applied through each window 112 (in step 206 of the method 200) comprises a ring-shaped element configured to press a ring-shaped area 147 of the head 118 of the positive tab 114a so that the head 118 is pressed against the positive terminal 122.

[0133] Similarly, the pressing apparatus may comprise a pair of spaced elements configured to press opposing ends 148 of the arcuate finger 119 of the negative tab 114b so that the arcuate finger 119 is pressed against the negative terminal 124.

[0134] In other embodiments, the ring-shaped element for pressing the head 118 may be replaced by two or more spaced elements configured to press areas close to the outer circumference of the head 118. Conversely, the pair of spaced elements for pressing the arcuate finger 119 may be replaced by a ring-shaped element configured to similarly press opposing ends of the arcuate finger 119.

[0135] The pressing apparatus may be spring-loaded, or similarly dampened with one or more resiliently compressible members. The pressing apparatus may additionally or alternatively comprise a force or pressure measurement device. The pressing apparatus may therefore be applied to press the tabs until a predetermined force or pressure is applied to the tabs by pressing them against respective terminals of the battery cells.

[0136] Once the tabs 114a, 114b are pressed against the respective terminals 122, 124, the laser welder is actuated to weld predetermined weld areas 149 of the tabs 114a, 114b. For example, for the positive tab 114a, the weld area 149 is ring-shaped. In other embodiments, the weld area may be circular or elliptical, or lines of weld may be applied, for example in an X-shape.

[0137] Meanwhile, the weld area 149 of the negative tab 114b is a straight line extending along the arcuate finger 119. In other embodiments, the weld area may be a curved line following the arc of the arcuate finger 119 or spot welds space along the arcuate finger 119, for example.

[0138] Step 208 includes actuating the laser welder to align itself for performing said weld based on one or more captured images of each of the battery cells 120 as viewed through the windows 112. More particularly, step 208 includes automatic identification of at least part of a circular edge of an end of said cylindrical cells.

[0139] In some embodiments, the laser welder and the pressing apparatus may be integrated as a single device. Accordingly, alignment of the laser welder may also provide alignment of the pressing apparatus. In other embodiments, the laser welder and the pressing apparatus may be separate devices and may therefore require separate alignment steps. Nevertheless, it will be appreciated that the pressing apparatus may be aligned very similarly to the alignment of the laser welder described herein.

[0140] With reference to Figure 16, the circular edge 121 is an inner circumference of the battery cell casing, i.e. an inner circumference of the negative terminal 124.

[0141] In theory, only a short portion of the circular edge 121 sufficient to reveal its curvature and estimate a centre of the arc is required for alignment of the laser welder and / or pressing apparatus. However, maximising visibility of the circular edge 121 enables the laser welder and / or pressing apparatus to be aligned with a respective battery cell more accurately.

[0142] Accordingly, the window 112 is sized and arranged to reveal at least part of the circular edge 121. In this embodiment, the window 112 also includes extended openings 113 in opposing corners of the window 112 to further improve the visibility of the circular edge 121. Furthermore, the arcuate finger 119 of the negative tab 114b includes a taper 146 along its length, specifically towards its end, wherein the taper 146 is configured to further reveal a part of the circular edge 121 of the can when viewed through the window 112. That being said, each window 112 cannot be enlarged to the extent that the cell connection assembly 100 loses structural strength. It is also important that a sufficient amount of electrically conductive material is provided in the first and second BTC layers 102, 104 to avoid unduly high electrical resistance. Similarly, each arcuate finger 119 should remain be large enough, despite any tapers 146, to enable a robust connection to the respective negative terminal 124.

[0143] A further consideration in the configuration of each window 112 is the role of the respective opening provided through each of the first, second and third insulation layers 106, 108, 110 (visible in Figure 5). Electrically conductive parts that may operate at different electrical potential or voltage levels in use, i.e., the first and second BTC layers, may require separation by a minimum distance as specified in industrial standards and depending on relevant design and manufacturing parameters. Thus, the electrical insulator forming each of the first, second and third insulation layers 106, 108, 110 may require configuration to guarantee suitable clearance distances between electrically conductive parts of the cell connection assembly 100, while taking into account manufacturing tolerances and potential creepage in use.

[0144] In this embodiment, there are three visible regions of the circular edge 121 and the length arc visible is nominally around 7.5 mm. However, it will be appreciated that the exact visibility requirements may be specific to a particular vision system used with a laser welder and / or pressing apparatus.

[0145] The instructions and / or flowchart steps in the above figures can be executed in any order unless a specific order is explicitly stated. Also, those skilled in the art will recognize that while one example set of instructions / method has been discussed, the material in this specification can be combined in a variety of ways to yield other examples as well and are to be understood within a context provided by this detailed description.

[0146] In some example embodiments the set of instructions / method steps described above are implemented as functional and software instructions embodied as a set of executable instructions which are put into effect on a computer or machine which is programmed with and controlled by said executable instructions. Such instructions are loaded for execution on a processor (such as one or more CPUs). The term processor includes microprocessors, microcontrollers, processor modules or subsystems (including one or more microprocessors or microcontrollers), or other control or computing devices. A processor can refer to a single component or to plural components.

[0147] In other examples, the set of instructions / methods illustrated herein and data and instructions associated therewith are stored in respective storage devices, which are implemented as one or more non-transient machine or computer- readable or computer-usable storage media or mediums. Such computer- readable or computer usable storage medium or media is (are) considered to be part of an article (or article of manufacture). An article or article of manufacture can refer to any manufactured single component or multiple components. The non-transient machine or computer usable media or mediums as defined herein excludes signals, but such media or mediums may be capable of receiving and processing information from signals and / or other transient mediums.

[0148] In one example, one or more instructions or steps discussed herein are automated. The terms automated or automatically (and like variations thereof) mean controlled operation of an apparatus, system, and / or process using computers and / or mechanical / electrical devices without the necessity of human intervention, observation, effort and / or decision.

[0149] It will be appreciated that any components said to be coupled may be coupled or connected either directly or indirectly. In the case of indirect coupling, additional components may be located between the two components that are said to be coupled.

[0150] In this specification, example embodiments have been presented in terms of a selected set of details. However, a person of ordinary skill in the art would understand that many other example embodiments may be practiced which include a different selected set of these details. It is intended that the following claims cover all possible example embodiments.

Claims

CLAIMS1. A cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane for coupling the battery cells via connection to a positive or a negative terminal of the battery cells; a second battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a second plane for coupling the battery cells via connection to a positive or a negative terminal different from the positive or negative terminals to which the first battery-terminal-connecting layer is configured for connection; a first insulation layer comprising an electrical insulator, arranged between the first battery-terminal-connecting layer and the second batteryterminal-connecting layer, in a third plane; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement; wherein the current collector of the first battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window, the flexible projection configured to be pressed out of the first plane to secure it to the respective terminal; and wherein the current collector of the second battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window, the flexible projection configured to be pressed out of the second plane to secure it to the respective terminal.

2. The cell connection assembly of claim 1, wherein the tabs are each configured to flex when pressed against a respective terminal and are configured for laser welding thereto through the window.

3. The cell connection assembly of claim 1 or claim 2, wherein the laminated structure comprises one or both of: a second insulation layer comprising an electrical insulator arranged adjacent the first battery-terminal-connecting layer and opposed the first insulation layer; and a third insulation layer comprising an electrical insulator arranged adjacent the second battery-terminal-connecting layer and opposed the first insulation layer.

4. The cell connection assembly of any preceding claim, wherein one of the first and second battery-terminal-connecting layers comprises a first main connector that extends out from the laminated structure to provide a negative terminal for the plurality of battery cells that are electrically connected by the cell connection assembly; and one of the first and second battery-terminal-connecting layers comprises a second main connector that extends out from the laminated structure to provide the positive terminal for the plurality of battery cells that are electrically connected by the cell connection assembly.

5. The cell connection assembly of claim 4, wherein the first main connector and the second main connector extend from a common edge of the laminated structure of the cell connection assembly.

6. The cell connection assembly of claim 5, wherein the first main connector and the second main connector extend from the common edge in a first direction for securement to further parts and at least a subset of the plurality of tabs are configured to project into their respective windows at an angle greater than 30 degrees from the first direction.

7. The cell connection assembly of any preceding claim, wherein the at least first and second battery-terminal-connecting layers provide for electricalconnection to all terminals of the plurality of battery cells at a single side of the arrangement of the plurality of battery cells.

8. The cell connection assembly of any preceding claim, wherein one or both of: the current collector of the first battery-terminal-connecting layer comprises a first row part and a separate, second row part arranged side-by- side in the first plane, wherein the first row part and the second row part are connected at a first end of the first battery-terminal-connecting layer by a first connector layer, the first connector layer comprising an electrically conductive, substantially U-shaped member extending substantially perpendicular to the first plane; and the current collector of the second battery-terminal-connecting layer comprises a first row part and a separate, second row part arranged side-by- side in the second plane, wherein the first row part and the second row part are connected at a first end of the second battery-terminal-connecting layer by a second connector layer, the second connector layer comprising an electrically conductive, substantially U-shaped member extending substantially perpendicular to the second plane.

9. The cell connection assembly of claim 8, wherein, respectively, one or both of: one or more of the first row part of the first battery-terminal-connecting layer, the second row part of the first battery-terminal-connecting layer, and the first connector layer, include cut-outs or notches to increase electrical resistance in a region to control current density when current flows between the first row and the second row through the first connector layer; one or more of the first row part of the second battery-terminalconnecting layer, the second row part of the second battery-terminalconnecting layer, and the second connector layer, include one or more cut-outs or notches to increase the electrical resistance in a region to control current density when current flows between the first row and the second row through the second connector layer.

10. The cell connection assembly of any preceding claim, wherein the plurality of tabs of the first battery-terminal-connecting layer and the plurality of tabs of the second battery-terminal-connecting layer are one or both of a positive tab type and a negative tab type, wherein the positive tab type is configured to couple to the positive terminal of the plurality of battery cells and the negative tab type is configured to couple to the negative terminal of the plurality of battery cell.

11. The cell connection assembly of claim 10, wherein the positive tab type comprises an elongate arm projecting into the window and a head at the distal end of the elongate arm to electrically couple to the positive terminal.

12. The cell connection assembly of claim 10 or claim 11, wherein the negative tab type comprises an arcuate finger projecting into the window to electrically couple to the negative terminal, wherein the plurality of battery cells comprise cylindrical cells and the negative terminal comprise a ringshaped edge of a can of said cylindrical cells.

13. The cell connection assembly of claim 12, wherein the arcuate finger includes one or more tapers along its length configured to reveal parts of the ring-shaped edge of the can when viewed through the windows.

14. The cell connection assembly of any preceding claim, wherein the plurality of battery cells comprises cylindrical cells and each of the windows is sized and arranged to reveal at least part of a circular edge of the negative terminal of said cylindrical cells.

15. The cell connection assembly of claim 10, wherein: the current collector of the first battery-terminal-connecting layer comprises a plurality of separate sub-collectors in the first plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of a first parallel subset of battery cells of the plurality of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a second parallel subset of battery cells, andthe current collector of the second battery-terminal-connecting layer comprises a plurality of separate sub-collectors in the second plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of said second parallel subset of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a third parallel subset of battery cells.

16. A method of electrically coupling a cell connection assembly with positive and negative terminals of an arrangement of a plurality of battery cells, the method comprising: receiving the arrangement of the plurality of battery cells; receiving a cell connection assembly of any preceding claim and aligning the cell connection assembly relative to the arrangement of the plurality of battery cells; applying a pressing apparatus through the plurality of windows to press the plurality of tabs of the first battery-terminal-connecting layer out of the first plane and the plurality of tabs of the second battery-terminal-connecting layer out of the second plane and to press the tabs of the first and second battery-terminal-connecting layers against respective positive and negative terminals of the plurality of battery cells; and actuating a laser welder to weld the tabs to the respective positive and negative terminals.

17. The method of claim 16, wherein the method includes actuating the laser welder to align itself for performing said weld based on one or more captured images of each of the battery cells as viewed through the windows.

18. The method of claim 16, wherein said plurality of battery cells comprises cylindrical cells and the step of actuating the laser welder to align itself comprises aligning based on one or more captured images of each of the battery cells as viewed through the windows and automatic identification of at least part of a circular edge of an end of said cylindrical cells.

19. A battery-terminal-connecting layer for forming part of a cell connection assembly for electrically coupling positive and negative terminals of anarrangement of a plurality of battery cells, the battery-terminal-connecting layer comprising: an electrically conductive current collector arranged in a first plane for coupling to one of the positive and negative terminals or both positive and negative of the battery cells, the current collector comprising a first row part and a separate, second row part arranged side-by-side in the first plane; and an electrically conductive connector layer connecting the first row part and the second row part at a first end of the first battery-terminal-connecting layer, the connector layer extending substantially perpendicular to the first plane.

20. The battery-terminal-connecting layer of claim 19, wherein the connector layer comprises a substantially U-shaped member.

21. The battery-terminal-connecting layer of claim 19 or claim 20, wherein one or more of the first row part, the second row part and the connector layer, include cut-outs or notches to increase the electrical resistance in a region to control current density when current flows between the first row and the second row through the connector layer.

22. A cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane for coupling to one of the positive and negative terminals or both positive and negative terminals of the battery cells, and a first main connector that extends out from the laminated structure to provide a positive terminal for the plurality of battery cells that are electrically connected by the cell connection assembly; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement;wherein the current collector of the first battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window; and wherein the first main connector extends from the laminated structure in a first direction for securement to further parts and at least a subset of the plurality of tabs are configured to project into their respective windows at an angle greater than 30 degrees from the first direction.

23. The cell connection assembly of claim 22, wherein the subset of the plurality of tabs are configured to project into their respective windows at an angle of between 30 and 150 degrees to the first direction.

24. A cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane for coupling to one of the positive and negative terminals or both positive and negative terminals of the battery cells, and a first main connector that extends out from the laminated structure to provide a positive terminal for the plurality of battery cells that are electrically connected by the cell connection assembly; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement; wherein the current collector of the first battery-terminal-connecting layer includes a plurality of tabs, each tab comprising a flexible projection configured to project into one of the plurality of windows to electrically couple to a different, respective terminal of the one or more battery cells aligned with that window, the flexible projection configured to be pressed out of the first plane to secure it to the respective terminal; andwherein the plurality of battery cells comprises cylindrical cells and each of the windows is sized and arranged to reveal at least part of a circular edge of an end of said cylindrical cells.

25. The cell connection assembly of claim 24, wherein the plurality of tabs of the first battery-terminal-connecting layer and the plurality of tabs of the second battery-terminal-connecting layer are one or both of a positive tab type and a negative tab type, wherein the positive tab type is configured to couple to the positive terminal of the plurality of battery cells and the negative tab type is configured to couple to the negative terminal of the plurality of battery cell.

26. The cell connection assembly of claim 25, wherein the negative tab type comprises an arcuate finger extending from either the respective batteryterminal-connecting layer into the window to electrically couple to the negative terminal, wherein the plurality of battery cells comprise cylindrical cells and the negative terminal comprise a ring-shaped edge of a can of said cylindrical cells.

27. The cell connection assembly of claim 26, wherein the arcuate finger includes one or more tapers along its length configured to reveal parts of the ring-shaped edge of the can when viewed through the windows.

28. A cell connection assembly for electrically coupling positive and negative terminals of an arrangement of a plurality of battery cells, the cell connection assembly comprising a laminated structure of a plurality of layers comprising at least: a first battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a first plane, the current collector comprising a plurality of separate sub-collectors in the first plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of a first parallel subset of battery cells of the plurality of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of a second parallel subset of battery cells;a second battery-terminal-connecting layer comprising an electrically conductive current collector arranged in a second plane, the current collector comprising a plurality of separate sub-collectors in the second plane, wherein at least one of the sub-collectors comprises a plurality of tabs of positive tab type for electrically coupling to the positive terminals of the second parallel subset of battery cells and a plurality of tabs of negative tab type for electrically coupling to the negative terminals of third parallel subset of battery cells; a first insulation layer comprising an electrical insulator, arranged between the first battery-terminal-connecting layer and the second batteryterminal-connecting layer in a third plane; wherein the laminated structure includes a plurality of windows each providing an opening in the laminated structure, each window configured to align with one or more battery cells of the plurality of battery cells when the cell connection assembly is placed adjacent the arrangement and enable access to respectively aligned tabs of the first and second battery-terminal-connecting layers.

29. A battery system comprising: the cell connection assembly of any of claims 1 to 15 and 22 to 28; or the battery-terminal-connecting layer of any of claims 19 to 21.

30. A vehicle including a battery system comprising: the cell connection assembly of any of claims 1 to 15 and 22 to 28; or the battery-terminal-connecting layer of any of claims 19 to 21.

Images