Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/502—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing
  • H01M50/507—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing comprising an arrangement of two or more busbars within a container structure, e.g. busbar modules
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
  • H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
  • H01M50/207—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape
  • H01M50/213—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape adapted for cells having curved cross-section, e.g. round or elliptic
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
  • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/502—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/502—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing
  • H01M50/503—Interconnectors for connecting terminals of adjacent batteries; Interconnectors for connecting cells outside a battery casing characterised by the shape of the interconnectors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2220/00—Batteries for particular applications
  • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to batteries and, particularly, but not exclusively, to a battery module and a battery pack comprising the battery module.
• the battery module and the battery pack are suitable for an electric vehicle, among other uses.
• Batteries are an integral part of many electrical and electronic systems, including electric vehicles and energy storage devices.
• Battery packs may often be comprised of a plurality of individual battery cells electrically connected to form one or more battery modules. It can be challenging to electrically connect the battery cells in such a way as to provide a desired electrical output of a battery module in an efficient manner whilst reducing losses, weight and cost, and improving ease of manufacture.
• a battery module comprising a plurality of battery cells arranged in first and second banks, each battery cell comprising a first end supported on a base and a second end, opposite the first end, comprising a first-polarity terminal and a second-polarity terminal, a first busbar overlying the plurality of battery cells and a second busbar overlying the first busbar.
• the first busbar comprises a plurality of first-polarity connection portions electrically connected to the first-polarity terminals of each battery cell in the first bank of battery cells, and a plurality of second-polarity connection portions interspersed with apertures, the second-polarity connection portions electrically connected to the second-polarity terminals of each battery cell in the second bank of battery cells, and the apertures aligned with the first-polarity terminals of each battery cell in the second bank of battery cells.
• the second busbar comprises a plurality of first-polarity connection portions connected through the apertures of the first busbar to the first-polarity terminals of each battery cell in the second bank of battery cells.
• the battery module may thereby comprise two layers of busbars. This may provide a greater area over which to transmit current to and from the battery cells, and may thereby permit a greater amount of total current to flow through the busbars when compared to a single layer of busbars of the same thickness as each of the busbars in the two layers.
• each of the first and second busbars in a two-layer configuration may have half the thickness of a comparable single-layer busbar whilst providing the same overall current draw characteristics. Thinner busbars may improve the ease of manufacture, for instance by improving an ease of welding, or a quality of a weld, between a connection portion and a battery cell terminal, particularly if the battery cell terminal is relatively thin.
• the battery module may be for an electric vehicle.
• the first-polarity may be positive and the second-polarity may be negative, or vice versa.
• the plurality of battery cells may be arranged into rows, and each of the first bank and the second bank of battery cells may comprise a plurality of battery cells from a single row or from multiple rows.
• the plurality of battery cells may be hexagonally close-packed.
• the first-polarity terminal of each battery cell may comprise one of a central projection on the second end of the battery cell and an annular portion on the second end of the battery cell, the annular portion concentric around the central projection.
• the second- polarity terminal of each battery cell may comprise the other of the central projection and the annular portion.
• the annular projection may be defined by a rim, or an edge, of an outer shell, or canister of the battery cell.
• the battery module may comprise a plurality of battery cells arranged in a third bank of battery cells, and the second busbar may comprise a plurality of second-polarity connection portions connected to the second-polarity terminals of each battery cell in the third bank of battery cells.
• the third bank of battery cells is connected to the first bank of battery cells in series.
• the battery module may comprise a third busbar underlying the second busbar and coplanar with the first busbar, the third busbar comprising a plurality of first-polarity connection portions interspersed with apertures, the first polarity connection portions electrically connected to the first-polarity terminals of each battery cell in the third bank of battery cells, and the apertures aligned with the second-polarity terminals, of each battery cell in the third bank of battery cells.
• the busbars may be substantially planar.
• One or more coplanar busbars may be located slightly above or below a common plane, for instance located a distance of up to twice, up to five times, or up to ten times an average thickness of one or more busbars above or below the common plane.
• the common plane may be defined by one or more of the coplanar busbars.
• the plurality of second-polarity connection portions of the second busbar may be electrically connected through the apertures of the third busbar to the second-polarity terminals of each battery cell in the third bank of battery cells.
• the first-polarity connection portions of the first busbar may be interspersed with apertures and the battery module may comprise a fourth busbar overlying the first busbar and coplanar with the second busbar, the fourth busbar comprising a plurality of second- polarity connection portions electrically connected, through the apertures that are interspersed with the first-polarity connection portions of the first busbar, to the second- polarity terminals of each battery cell in the first bank of battery cells.
• One or more connection portions may be directly connected to respective battery cell terminals.
• connection may be made by welding, or bonding the one or more connection portions to respective battery cell terminals.
• connection portions may be indirectly connected to respective battery cell terminals.
• the connection may be made by a wire bond.
• the apertures may at least partly conform to the shape of respective underlying terminals with which they are aligned.
• the apertures of an underlying busbar may at least partly conform to a shape of respective connection portions of an overlying busbar.
• the apertures may improve access to the respective battery cell terminals by the connection portions while maintaining a large busbar surface area, for instance to accommodate a higher current flowing through the busbars.
• the busbars may be the same shape as one another.
• the busbars may form a repeating pattern when arranged in the battery module. This may improve an ease of manufacturing the busbars, and/or reduce a cost of manufacturing the busbars.
• the busbars may be formed using a single template, and optionally from a single sheet of material. A smaller tool may be used to form the repeating pattern when compared to a tool required to form a single pattern across a full extent of the battery module, for instance.
• the busbar material may be a conductive material, such as copper.
• Each busbar may comprise a planar main body and integrally-formed connection portions depending from the main body toward the respective terminals.
• connection portions may be located closer to respective battery cell terminals than the main body. In this way, if the connection portions are indirectly connected to respective battery cell terminals, for instance by a wire bond, then the wire bond may be shorter. This may reduce a material cost and/or improve ease of manufacture.
• connection portions may depend from the main body to directly connect to respective battery cell terminals. This may provide a reliable connection between the busbars and respective battery cell terminals.
• the main body may be spaced from the battery cell terminals. This may reduce a risk of damaging the battery module, for instance by shorting between a busbar and respective underlying battery cells.
• Each connection portion may comprise one of a central connection point aligned with a centre of a terminal, the central connection point comprising a plurality of arms circumferentially spaced around the connection point to connect the connection point to the main body; and one or more perimetric connection points aligned with a perimeter of a respective terminal, each perimetric connection point depending from the main body.
• Each busbar may comprise a plurality of central regions, each central region aligned with an underlying battery cell terminal.
• the central connection points may be located in a centre of a respective central region.
• the perimetric connection points may be circumferentially spaced around a respective central region.
• the second-polarity connection portion may comprise the other of the central connection point and the one or more perimetric connection points.
• the central region may be circular, hexagonal, triangular, or any other suitable shape.
• the shape of the central region may correspond to the shape of the underlying battery cell.
• the central connection point may connect the busbar to a respective battery cell terminal.
• the main body may be shaped to conform to a perimeter of the central region.
• the perimetric connection points may comprise tabs depending from the main body.
• the number of perimetric connection points of a connection portion may be the same as the number of arms of an overlying or underlying connection portion. Each perimetric connection point may be aligned with a respective aperture defined between the arms of a connection portion of an overlying or underlying busbar.
• the central connection points, the arms and the main body of the busbar together define a plurality of first-polarity or second-polarity apertures through which the perimetric connection portions are connected to respective first-polarity or second- polarity terminals.
• the arms and/or the perimetric connection points may be evenly distributed around the central region.
• the arms and/or the perimetric connection points may be unevenly spaced around the central region.
• the arms may form a Y-shaped connection portion, for instance aligned with a direction of current flow through the busbar. This may improve a directionality of the current flow, for instance to minimise losses due to current flowing in different directions through the busbar.
• the central connection point may comprise three arms, and one of the arms may be up to twice as wide as each of the other two arms.
• the wider arm may be up to three times wider than each of the perimetric connection portions.
• the wider arm may provide similar resistance characteristics to two smaller arms, each smaller arm belonging to one of two adjacent connection portions, or to a single adjacent connection portion, and the wider arm and the two smaller arms substantially aligned in the direction of aggregate current flow through the busbar. This may permit a more even current flow through the busbar.
• the busbars may be arranged so that an aggregate current flows in one direction through the battery module.
• the busbars may be arranged so that the aggregate current flows in a minor direction of the battery module.
• the minor direction may be a shortest dimension of the battery module. In this way, each busbar may be shorter in length, thereby reducing a resistance of the busbar and/or permitting the use of a thinner busbar.
• the plurality of battery cells may be supported by a battery cell carrier.
• the battery cell carrier may comprise mounting features for mounting the busbars spaced above the battery cells.
• the mounting features may be configured to align the connection portions of busbars with respective battery cell terminals.
• the battery module may comprise a layer of insulative material disposed between the layers of busbars.
• the cell carrier may be formed from insulative material and may isolate the main bodies of the busbars from the battery cell terminals.
• the battery cell carrier may comprise carrier apertures therethrough aligned with respective first-polarity and second-polarity apertures, and respective first-polarity and second-polarity connection portions.
• a second aspect of the present invention provides a battery pack comprising a plurality of battery modules according to the first aspect.
• the battery pack may be for an electric vehicle.
• a third aspect of the present invention provides an electric vehicle comprising a battery module according to the first aspect, or a battery pack according to the second aspect.
• Figure l is a schematic view of an arrangement of battery modules in a battery pack according to an example
• Figure 2A is a schematic view of a cell group of a battery module of the battery pack of Figure 1, showing battery cells and a part of a busbar arrangement comprised therein;
• Figure 2B is a side-elevation and plan view of the battery cells of Figure 2A;
• Figure 3 is a simplified cross-sectional schematic view of a part of the busbar arrangement of Figure 2 A;
• Figure 4 is a more detailed schematic view of a part of a busbar according to an example
• Figure 5 is an isometric expanded view of a busbar arrangement showing an insulating layer and a carrier layer, according to an example
• Figure 6 is an illustrative plan view of the busbar arrangement of Figure 5;
• Figure 7A is a schematic side elevation view of an electric vehicle according to an example, comprising a battery pack according to Figure 1;
• Figure 7B is a schematic plan view of an underside of the electric vehicle of Figure 7A.
• the battery module may be part of an arrangement of battery modules forming at least part of a battery pack.
• Examples of the invention will be described in the context of an electric vehicle. It will be understood that the invention is not limited to this purpose and may be applied to supply and/or store electrical energy for any kind of industrial, commercial or domestic purpose, for example in smart grids, home energy storage systems, electricity load balancing and the like.
• battery may be used interchangeably and may refer to any of a variety of different battery cell types and configurations including, but not limited to, lithium ion, lithium ion polymer, nickel metal hydride, nickel cadmium, nickel hydrogen, alkaline, or other battery cell type/configuration.
• FIG. 1 shows a schematic view of a battery pack 10 comprising an arrangement of battery modules lOOa-lOOc and a battery management system 200.
• the battery modules lOOa-lOOc may generally be referred to herein using the reference numeral 100.
• the battery pack 10 has a first dimension 11 and a second dimension 12, respectively, corresponding to a width and a length dimension of the battery pack 10, respectively.
• the first and second dimensions 11, 12 may alternatively be referred to as ‘x’ and ‘y’ dimensions.
• a third dimension 13, which is also referred to herein as a ‘z’ dimension, is orthogonal to the first and second dimensions 11, 12 and corresponds with a depth or height dimension of the battery pack 10.
• the first dimension 11 is also a minor dimension of the battery pack 10 in the x-y plane.
• the first dimension 11 may be a major dimension of the battery pack 10 in the x-y plane, or the battery pack 10 may be equilateral in the x and y dimensions.
• the terms “major dimension” and “minor dimension” refer, respectively, to the longest and shortest spans or lengths of a structure. The major dimension is typically (as is the case herein), but not exclusively, perpendicular to the minor dimension.
• the battery modules lOOa-lOOc of the present example each comprise a plurality of battery cells (as shown in Figure 2a) arranged into groups 110 of battery cells, referred to herein generically as “cell groups 110”.
• Each battery module l lOa-lOOc of Figure 1 comprises a respective support 120a-120c and four cell groups 110 mounted on the respective support 120a- 120c.
• the battery module 100a comprises a first cell group 110a, a second cell group 110b, a third cell group 110c and a fourth cell group l lOd.
• the support 120a of the battery module 100a is planar and comprises opposing first and second faces 121, 122.
• the cell groups l lOa-l lOd are arranged with two cell groups 110a, 110b mounted spaced apart on the first face 121 of the support 120a and two cell groups 110c, 1 lOd mounted spaced apart on the second face 122 of the support 120a.
• a first channel 123 is defined between the cell groups 110a, 110b on the first face 121 and a second channel 124 is defined between the cell groups on the second face 122.
• each of the supports 120a-120c is also shown as being a generally regular, rectangular, plate-like member, comprising a major and a minor dimension, and supporting generally cuboidal cell groups l lOa-l lOd. In this way, the supports are elongate.
• the channels 123, 124 of a battery module lOOa-lOOc extend in a minor dimension of a respective support 120a-120c.
• any number of cell groups 1 lOa-1 lOd are mounted on the support 120a.
• the cell groups l lOa-l lOd are mounted on only one of the first and second faces 121, 122.
• each of the supports 120a-120c is a cooling member.
• the battery modules lOOa-lOOc are arranged in the battery pack 10 of Figure 1 side-by- side, width wise, adjacent to and coplanar with one another in the second dimension 12 such that the cell groups 1 lOa-1 lOd of each battery module lOOa-lOOc are aligned with corresponding cell groups 1 lOa-1 lOd of each other battery module lOOa-lOOc.
• coplanar as used herein is inclusive of slight deviations in a location of an element from a plane.
• one or more battery modules lOOa-lOOc may be located slightly above or below a plane of the battery pack 10, for instance located a distance of up to twice, or up to five times an average thickness of one or each support 120a-120c above or below a plane defined by one or more of the supports 120a-120c.
• the term “coplanar” may be defined in a similar way in relation to an average thickness of busbars, rather than in relation to an average thickness of the supports 120a-120c.
• first and second channels 123, 124 of each battery module lOOa-lOOc in the example of Figure 1 are longitudinally aligned with corresponding first and second channels 123, 124 of each other battery module 100a- 100c.
• the alignment of first channels 123 forms a first longitudinal passage 14 between cell groups 110a, 110b in the battery pack 10
• the alignment of second channels 124 forms a second longitudinal passage 15 between cell groups 110c, l lOd in the battery pack 10.
• the first and second longitudinal passages 14, 15 extend parallel with the second dimension 12 of the battery pack 10.
• the battery modules lOOa-lOOc are spaced apart along the second dimension 12 of the battery pack 10 to form a plurality of transverse passages 16 in the battery pack 10.
• the transverse passages 16 of the illustrated example extend in the first dimension 11 of the battery pack 10.
• the battery management system 200 of the present example comprises a controller 210.
• the controller 210 is communicatively coupled to each cell group 110 in each battery module 220 by communication lines 220.
• the communication lines 220 comprise wires.
• the communication lines 220 comprise busbars.
• communication between the controller 210 and the cell groups 110 may instead, or in addition, be wireless.
• the battery modules lOOa-lOOc are electrically connected to one another and to the controller 210 by module connections 221. That is, cell groups 110 of each battery module 100 are connected to cell groups 110 of adjacent battery modules 100 via module connections 221.
• the module connections 221 between cell groups 110 of adjacent battery modules 100 are located in respective transverse passages 16.
• each cell group 110 is connected in series to other cell groups 110 in the same row, so that an aggregate current flows in the second, major dimension 12 of the battery pack 10.
• Each cell group l lOa-l lOd in a battery module 100a is electrically isolated from each other cell group l lOa-l lOd on the same support 120a, at least until the battery module 100a is connected to other battery modules 100b, 100c in the battery pack 10.
• cell groups 110a, 110b on the first face 121 of a support 120a at an end of the battery pack 10 in the second dimension 12 are connected to cell group 110c, l lOd on the second face 122 of the support 120a.
• the cell groups 110a, 110c are electrically isolated from adjacent cell groups 110b, l lOd on the same support 120a by a respective channel 123, 124 and/or longitudinal passage 14, 15.
• the controller 210 of the battery management system 200 is configured to vary an electrical output of the battery pack 10, and/or to reconfigure the battery pack 10.
• the battery modules lOOa-lOOc are electrically connected to a controller other than the controller 210 shown in Figure 1.
• the controller 210 is configured to detect and/or monitor one or more properties of the cell groups 110 of each battery module lOOa-lOOc, as will be described hereinafter with reference to Figure 2.
• FIG 2 A shows a simplified schematic view of a cell group 110 of one battery module lOOa-lOOc of Figure 1, showing the battery cells 130 in the cell group 110.
• the cell group 110 comprises a plurality of battery cells 130 arranged in a two-dimensional array 140.
• the array 140 has a major dimension parallel to the x-axis and a minor dimension parallel to the y-axis.
• the battery cells 130 in the array 140 are arranged into a plurality of banks (or sub-groups) 150a-150e of battery cells 130.
• the banks 150b, 150d of battery cells 130 in Figure 2A are filled white and the banks 150a, 150c, 150e are hatched to distinguish the banks 150a-150e of battery cells 130 from one another.
• the banks 150a-150e may generally be referred to herein using the reference numeral 150.
• each bank 150a-150e comprising eight or nine battery cells 130.
• the battery cells 130 are arranged into rows, the rows extending in the major dimension of the array 140.
• the banks 150a-150e span a length of the cell group 110 in the major dimension, and each bank 150a-150e is confined to a single row in the array 140.
• each bank 150a-150e is generally a one-dimensional rectangular array.
• each bank 150a-150e of parallel-connected battery cells 130 does not span the entire length of the cell group 110 in the major dimension thereof, and that the banks 150a-150e span multiple rows in the array 140, or are not confined to such rows or rectangular arrays. That is, in other examples, each of the banks 150a-150e comprise battery cells in two or more rows.
• FIG. 2B shows a side-elevation and a plan view of a battery cell 130.
• the battery cell 130 comprises a first end 131 and a second end 132, opposite to the first end 131.
• the second ends 132 of each of the battery cells 130 in the cell group 110 are secured, in this example, to a face 121, 122 of a respective support 120a-120c, whereby the first ends 131 of the battery cells 130 are generally coplanar, residing in a plane that is parallel to a plane of the respective support 120a-120c.
• the battery cells 130 of the present example each comprise first-polarity and second- polarity battery cell terminals 133, 134 at respective first ends 131, the first-polarity and second-polarity terminals 133, 134 being of opposite polarity.
• the battery cell terminals 133, 134 of each of the battery cells 130 are exposed on the first ends 131 of the battery cells 130, away from respective supports 120a-120c.
• the first- polarity terminal 133 is a positive terminal 133 of the battery cell 130
• the second- polarity terminal 134 is a negative terminal 134 of the battery cell 130. It will be understood that, in other examples, the polarities of the battery cell terminals 133, 134 may be reversed.
• the positive terminal 133 comprises a central projection 133 on the first end 131 of the battery cell 130 and the negative terminal 134 comprises an annular portion 134 on the first end 131 of the battery cell 130 around the central projection 133.
• the annular portion 133 is defined by a rim, or an edge, of an outer shell, or canister of the battery cell 130. It will be understood that the positive and negative battery cell terminals 133, 134 of the battery cells 130 of the present invention are not limited to such shapes and may instead be any other shape suitable for facilitating respective positive and negative connections to the battery cells 130.
• the battery cells 130 of a cell group 110 may be mounted on a respective support 120a-120c by any appropriate method, including but not limited to, with adhesive, with fixing mechanisms such as clasps, clamps, braces, or by any other suitable attachment mechanisms.
• the battery cells 130 are supported at respective second ends 132 in a tray (not shown in Figure 2B).
• the tray comprises a plurality of recesses into each of which is received the second end 132 of a respective battery cell 130.
• the tray is mounted to a respective support 120a-120c. In other examples, the tray may not exist, and the respective support 120a-120c may be formed to receive the battery cells 130. That is, the respective support 120a-120c may have least one recess into which a battery cell 130 or a cell group 110 is received and mounted thereon.
• the supports 120a- 120c are constructed from electrically conductive material, and battery cells 130 are electrically isolated from the supports 120a-120c by the tray, which is constructed from electrically insulative material.
• the tray is thermally conductive.
• the tray may be thermally insulative.
• the supports 120a-120c may not be electrically conductive.
• the cell group 110 of the illustrated example comprises a busbar arrangement 160 comprising a plurality of busbars 161, specifically four busbars 161a- 161d.
• the busbars 161 extend in the major dimension of the cell group 110.
• the busbars 161 are shown in Figure 2 as extending only part way along the cell group 110.
• the busbars 161a-161e each extend along a length of the cell group 110 in the x-direction, as illustrated by the dashed line extending from one of the busbars 161a in Figure 2 A.
• the busbar arrangement 160 comprises alternating underlying 161b, 161d and overlying 161a, 161c busbars, as will be described hereinafter with reference to Figure 3.
• one busbar 161a electrically connects, in parallel, battery cells 130 in at least one bank 150a-150e of battery cells.
• the busbars 161 further connect adjacent banks 150a-150e of parallel-connected cells together in series.
• one or more of the busbars 161 a— 161 d may extend only part-way along the cell group 110 in the major dimension and connect to a subset of battery cells in a respective bank 150.
• the cell group 110 may comprise additional busbars 161 for connecting to the remaining battery cells 130.
• each busbar 161 is an elongate electrically conducting wire, plate or rod with connections (described in detail hereinafter) to positive or negative terminals 133, 134 of the battery cells 130 in a bank 150a-150e.
• one busbar 160a is configured to connect the positive battery cell terminals 133 of each battery cell 130 in one bank 150a of battery cells 130 to the negative battery cell terminal 134 of each battery cell 130 in an adjacent bank 150b of battery cells 130.
• a busbar 161 on a periphery of the cell group 110 (not shown in Figure 2A) is configured to connect the battery cells 130 of a respective peripheral bank 150a, 150e of battery cells 130 to one another in parallel.
• peripheral busbars 161 are configured to facilitate a connection between cell groups 110 of adjacent battery modules 100, for example via the module connections 221.
• the banks 150a-150e of battery cells 130 are connected such that current flows in series, via the busbars 161, between banks 150a-150e in the minor dimension of the cell group 110, as indicated by the arrow labelled I in Figure 2A.
• the current flow in a cell group 110 is, in the aggregate, perpendicular to a major dimension of each of the busbars 161, which are elongate and extend in the major dimension of the cell group 110.
• the aggregate current flow in cell group 110 is distributed evenly across the major dimension of the cell group 110.
• the direction is said to be ‘in the aggregate’, or ‘on average’, as there may be some minor deviations in current flow direction, for instance, which may be determined by the particular arrangement of the battery cells 130 and/or the shape of the busbars 161 connecting the battery cells 130, as will be described hereinafter with reference to Figures 4 to 6.
• the illustrated example comprises cell groups 110 having an aspect ratio of approximately 3:1 (that is, having a major dimension three times longer than a minor dimension).
• the cell groups 110 may therefore comprise busbars 161 which are in the order of three times thinner than those that would be required for a cell group 110 with an aspect ratio of 1 : 1, whilst providing the same current density in the busbars 161.
• busbars 161 may be thinner and lighter per unit area, which means they require less space per unit area and may be more easily formed, for instance, for the purposes of connecting to the terminals 133, 134 of individual battery cells 130. Furthermore, a shorter aggregate current path in a cell group 110 may lead to a reduced electrical resistance in the busbars 161, as resistance is proportional to the length of the current path.
• each bank 150 comprises battery cells 130 in a single row, and a busbar 161 electrically connects the battery cells 130 in the row to one another in parallel. It will be understood that, in other examples, each bank 150 comprises battery cells 130 in a plurality of rows, such as two or three rows, and a busbar 161 connects the battery cells 130 in each of the rows to one another in parallel.
• Figure 3 shows a simplified cross-sectional schematic view of a part of the cell group 110 and busbar arrangement 160 of Figure 2A.
• the battery cells 130 are shown in Figure 3 as being aligned in the y-direction.
• alternate battery cells 130 are arranged in a staggered arrangement in the y-direction. That is, the cells in the example of Figures 2A and 3, are hexagonally close-packed in the array 140.
• Each battery cell 130 in Figure 3 is comprised in a respective bank 150 of battery cells 130, the bank 150 extending in the x-direction.
• Figure 3 therefore shows an example of battery cells 130 in three banks 150b-150d of battery cells 130. That is, the cell group 100 comprises a first bank 150b, a second bank 150c, and a third bank 150d of battery cells. Other banks 150a, 150e are not shown.
• the busbar arrangement 160 of the illustrated example comprises four busbars 161a-161d. That is, the busbar arrangement 160 comprises a first busbar 161a, a second busbar 161b, a third busbar 161c, and a fourth busbar 161d.
• the second and fourth busbars 161b, 161d are located in a plane overlying the plurality of battery cells 130, and the first and third busbars 161a, 161c are located in a plane spaced from and overlying the second and third busbars 161b, 161d. That is, the first and third busbars 161a, 161c are coplanar, and the second and fourth busbars 161b, 161d are coplanar.
• the first and fourth busbars 161a, 161d extend in the y-direction to connect to battery cells 130 in banks 150a, 150e of battery cells 130 which are not shown in Figure 3.
• each busbar 161 comprises a plurality of positive connection portions 162a and a plurality of negative connection portions 162b connected to respective positive and negative terminals 133, 134 of underlying battery cells 130.
• Each underlying busbar 161b, 161d further comprises a plurality of apertures aligned with respective positive and negative terminals 133, 134 of underlying battery cells 130 and interspersed with respective positive and negative connection portions 162a, 162b.
• apertures interspersed with positive connection portions 162a and aligned with positive terminals 133 are referred to herein as “positive apertures 163a”.
• Apertures interspersed with negative connection portions 162b and aligned with negative terminals 134 are referred to herein as “negative apertures 163b”.
• the second busbar 161b comprises a plurality of positive connection portions 162a electrically connected to the positive terminals 133 of respective battery cells 130 in the first bank 150b of battery cells 130, and a plurality of negative connection portions 162b electrically connected to the negative terminals 134 of respective battery cells 130 in the second bank 150c of battery cells 130, adjacent to the first bank 150b.
• the second busbar 161b further comprises a plurality of positive apertures 163a aligned with positive terminals 133 of respective battery cells 130 in the second bank 150c of battery cells 130.
• the third busbar 161c overlying the second busbar 161b, comprises a plurality of positive connection portions 162a connected to the positive terminals 133 of respective battery cells 130 in the second bank 150c of battery cells 130, through the positive apertures 163a of the second busbar 161b.
• the third busbar 161c further comprises a plurality of negative connection portions 162b connected to the negative terminals 134 of respective battery cells 130 in the third bank 150d of battery cells 130, through negative apertures 133b of the fourth busbar 161d.
• this pattern is repeated in the y-direction.
• the positive connection portions 162a of overlying busbars 161a, 161c pass through the positive apertures 163a of respective underlying busbars 161b, 161d to connect to the positive terminals 133 of underlying battery cells 130.
• the negative connection portions 162b of overlying busbars 161a, 161c pass through the negative apertures 163b of respective underlying busbars 161b, 161d to connect to the positive terminals 133 of underlying battery cells 130.
• Figure 4 shows a part of a busbar 161 according to an example.
• the busbar 161 according to the example shown comprises a positive region 164a comprising a plurality of positive connection portions 162a and a negative region 164b comprising a plurality of negative connection portions 162b.
• the battery cells 130 are not shown in Figure 4, according to the present example there are three rows, extending in the x-direction, of battery cells 130 in each bank 150 of battery cells 130.
• the positive region 164a of the busbar 161 comprises three rows of positive connection portions 162a corresponding to battery cells 130 in respective rows of one bank 150 of battery cells.
• the negative region 164b comprises three rows of negative connection portions 162b corresponding to battery cells 130 in respective rows of an adjacent bank 150 of battery cells 130.
• the busbar 161 comprises a main body 165, and each positive and negative connection portion 162a, 162b is integrally formed with the main body 165.
• the positive and negative connection portions 162a, 162b depend from the main body 165 towards respective battery cell terminals 133, 134 of underlying battery cells 130.
• the busbar 161 comprises a plurality of central regions 166, each aligned with a respective underlying battery cell 130, and the positive and negative terminals 133, 134 thereof.
• Each central region 166 is shown with a dashed line in Figure 4.
• the positive and negative connection portions 162a, 162b are each defined with respect to a respective central region 166.
• the central regions are circular in shape, and conform to the shape of the positive and negative terminals 133, 134 of underlying battery cells 130.
• the central regions 166 may be any other shape, such as hexagonal or triangular, and/or may conform to the shape of underlying battery cells 130 and/or battery cell terminals 133, 134.
• each positive connection portion 162a comprises a central connection point 167a located at a centre of a respective central region 166 and depending from the main body 165.
• the central connection point 167a comprises three arms 168 circumferentially spaced around the central region 166 to connect the central connection point 167a to the main body 165.
• the positive connection portion of the present example is Y-shaped.
• the arms 168 are generally aligned with a direction of current flow through the busbar in the y-direction.
• the central connection point 167a comprises a recessed portion 173 between two of the arms 168 for connecting a wire bond (not shown in Figure 4) between the central connection point 167a and a positive terminal 133 of a respective battery cell 130.
• the recessed portion 173 may not exist, and/or the wire bond may not exist and the central connection point 167a may be directly connected to the positive terminal 133 of the respective battery cell 130.
• the main body 165 conforms to the shape of the central region 166 around each positive connection portion 162a. In this way, the central connection point 167a, the three arms 168 and the main body 165 of each positive connection portion 162a define three negative apertures 163b of the busbar 161.
• each negative connection portion 162b comprises perimetric connection points 167b circumferentially spaced around a perimeter of a respective central region 166.
• the perimetric connection points 167b depend from the main body 165 in the form of tabs, which are not visible in Figure 4.
• the perimetric connection points 167b are best shown in Figures 5 and 6, as described hereinafter. For clarity, Figure 4 instead shows apertures where the perimetric connection points 167b would be.
• the main body 165 in proximity to each negative connection portion 162b, conforms to the shape of a positive connection portion 162a to define a respective positive aperture 163a.
• the positive apertures 163b of one busbar 161 conform to the shape of respective positive connection portions 162a of an overlying busbar 161
• negative apertures 163b of the busbar 161 conform to the shape of negative connection portions 162b of the overlying busbar 161.
• the positive and negative apertures 163a, 163b may be any suitable shape that permits access to respective positive and negative terminals 133, 134 of underlying battery cells 130.
• the busbar 161 comprises mounting features in the form of mounting apertures 169.
• the mounting apertures 169 are configured to engage with corresponding mounting features of a cell group 110 to align the positive and negative connection portions 162a, 162b of the busbar 161 with respective positive and negative cell terminals 133, 134 of underlying battery cells 130, as described hereinafter with reference to Figure 5.
• Figure 5 show an isometric expanded view of the cell group 110 and busbar arrangement 160 showing two busbars 161b, 161c according to an example.
• Each busbar is shaped according to the example shown in Figure 4.
• the busbar arrangement 160 comprises, in a stacked arrangement: a carrier layer 170 located above the battery cells 130; a first busbar 161b located above the carrier layer 170; a second busbar 161c located above the first busbar 161b; and an insulation layer 180 located between the first and second busbars 161b, 161c.
• the positive connection portions 162a of each busbar 161b, 161c are connected to the positive terminals 133 of respective battery cells 130 by respective wire bonds 174.
• the negative connection points 167b of the negative connection portions 162b are directly connected to the negative terminals 134 of respective battery cells 130.
• the carrier layer 170 is shaped and arranged to support the battery cells 130 at respective first ends 131.
• the carrier layer may be configured to support the busbars 161 only.
• the carrier layer comprises mounting features in the form of carrier projections 171 for mounting the busbars 161b, 161c.
• the projections 171 are configured to engage with the mounting apertures 169 of the busbars 161b, 161c to align the busbars 161 with the battery cells 130 as described hereinbefore with reference to Figure 4.
• the projections 171 are configured to secure the busbars 161b, 161c to the carrier layer 170. This may be by the projections 171 being deformable once the arrangement has been assembled, or by the projections 171 comprising a notch or tab to engage with respective mounting apertures 169.
• the carrier layer 170 comprises a plurality of positive and negative carrier apertures 172a, 172b aligned with respective positive and negative connection portions 162a, 162b of the overlying busbars 161b, 161c.
• the positive carrier apertures 172a provide access to positive terminals 133 of underlying battery cells 130.
• each wire bond 174 connects a positive connection point 167a of an overlying busbar 161b, 161c to a positive terminal 133 of a respective underlying battery cell 130 via a respective positive carrier aperture 172a.
• the negative carrier apertures 172b of the present example conform to the shape of negative connection points 167b of overlying busbars 161b, 161c.
• the negative carrier apertures 172b permit connection of the negative connection points 167b to the negative terminals 134 of underlying battery cells 130 therethrough.
• the insulation layer 180 is constructed from electrically insulative material to prevent a short circuit between the first and second busbars 161b, 161c.
• the insulation layer 180 comprises positive insulation apertures 181a which are shaped to conform to positive connection portions 162a of the second busbar 161c passing therethrough.
• the insulation layer 180 further comprises negative insulation apertures 181b (not visible in Figure 5), which are shaped to conform to negative connection portions 162b of the second busbar 161c passing therethrough.
• the positive and negative insulation apertures 181a, 181b and/or the positive and negative carrier apertures 172a, 172b may be circular, or annular, or any other suitable shape to permit connection of the busbars 161b, 161c to underlying battery cells 130 therethrough.
• Figure 6 shows an illustrative plan view of a part of the cell group 110 and busbar arrangement 160 shown in Figure 5.
• the busbar arrangement 160 comprises one overlying busbar 161c and two underlying busbars 161b, 161d.
• the overlying busbar 161c is shaded darker than the underlying busbars 161b, 161d, and the carrier layer 170 is shaded lighter than all of the busbars 161b— 161d.
• the underlying battery cells 130 are not visible in Figure 6.
• each busbar 161 in the busbar arrangement 160 is the same shape as each other busbar 161.
• Each busbar 161 in the busbar arrangement 160 connects to an equal number of positive terminals 133 as negative terminals 134.
• busbars 161b, 161d are physically separated from one another by the carrier layer along the dashed line in the centre of Figure 6.
• the overlying busbar 161c is similarly separated from other overlying busbars 161 in the busbar arrangement 160 by the carrier layer along the dashed line to the left of Figure 6. This is to prevent a short circuit between the busbars 161s.
• FIG. 7A shows a schematic side elevation of an electric vehicle 20 comprising a battery pack 10 disposed in the electric vehicle 20.
• the battery pack 10 may be disposed towards a lower side of the electric vehicle 20, for instance in order to lower a centre of mass of the electric vehicle 20.
• FIG. 7B shows a schematic view of an underside of the electric vehicle 20.
• the electric vehicle 20 comprises a front electric drive unit 21 and a rear electric drive unit 22 for delivering power to driving wheels 23 of the electric vehicle 20.
• the battery pack 10 is located between the front and rear electric drive units 21, 22.
• the front and rear electric drive units 21, 22 each comprise invertors for converting DC battery current into AC current to be delivered to traction motors. In other examples, the inverters are not required.
• the battery pack 10 comprises an electrical connection 24 for connecting the battery pack 10 to the rear electric drive unit 22.
• the electrical connection 24 extends along at least one of the longitudinal passages 14, 15 of the battery pack 10.
• the battery pack 10 is arranged such that a battery input/output 25 is located towards the front electric drive unit 21 of the electric vehicle and the electrical connection 24 extends from the battery input/output 25 and along a longitudinal passage 14, 15 to the rear electric drive unit 22.
• the electrical connection is connected to the inverter of the rear electric drive unit.
• an electrical connection connecting the input/output 25 of the battery pack 10 to the front electric drive unit 21, or to a charging port of the electric vehicle 20, extends along a longitudinal passage 14, 15 of the battery pack 10.
• the battery input/output 25 is a part of the battery management system 200. In some examples, the battery input/output 25 is the controller 210. In some examples, the battery input/output 25 is located at any other location on the battery pack 10, such as towards a rear electric drive unit 22 of the electric vehicle 10.
• the battery pack 10 comprises eight battery modules 100, each comprising four cell groups 110. In some examples, there may be more than eight or fewer than eight battery modules 100 in a battery pack 10, and/or more than or fewer than four cell groups 110 in a battery module 100.
• the battery pack 10 is configurable to operate at either 400 volts (V) or 800 V. Operating the battery pack 10 at a particular voltage may comprise charging or delivering energy at that voltage. It will be understood that, in some examples, the battery pack 10 and the aggregate current paths or circuits comprised therein may be configured to operate at voltages other than those described. For example, a battery pack 10 configured for use in a home energy storage system or may operate at voltages lower than 400 V, while a battery pack 10 configured for industrial use may operate voltages higher than 800 V.
• V volts
• 800 V volts
• a battery pack 10 or a battery module 100 may instead be used to provide and store electrical energy for any kind of industrial, commercial, or domestic purposes, such as for energy storage and delivery, for example, in smart grids, home energy storage systems, electricity load balancing and the like.
• a battery pack 10 may comprise any number of battery modules 100, and the cell groups 110 may comprise any number of battery cells 130.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Battery Mounting, Suspending (AREA)
• Connection Of Batteries Or Terminals (AREA)

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• 2019
  • 2019-12-19 GB GB1918800.2A patent/GB2590460B/en active Active
• 2020
  • 2020-10-14 WO PCT/GB2020/052565 patent/WO2021123712A1/en active Application Filing
  • 2020-10-14 CN CN202080096175.0A patent/CN115066799A/zh active Pending

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