TRACTION BATTERY BUSBAR SUPPORT FOR PLUG-IN BATTERY CELLS

Abstract

Traction battery assembly (24) comprising: an array (104) of plug-in battery cells (120) each having terminal tabs (124) extending from opposite side surfaces of the cells (120); a pair of conductor supports (112) each extending along opposite sides of the assembly (104) and configured to have the terminal tabs (124) pass therethrough; a pair of end plates (110) attached to the supports (112) and arranged with the supports (112) to hold the assembly (104) therebetween; and first and second groups of spaced-apart busbars (160), each of which is secured to one of the supports (112) in such a way that the groupings are offset from one another and are arranged with adjacent terminal tabs (124) in order to conductively connect the plug-in battery cells (120) in series.

Description

TECHNICAL FIELD

[0001] This disclosure relates to support structures for high voltage batteries used in vehicles. BACKGROUND

[0002] Vehicles such as battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), mild hybrid electric vehicles (MHEVs), or full hybrid electric vehicles (FHEVs) include an energy storage device, such as a high-voltage (HV) battery, intended to act as a power source for the vehicle. The HV battery may include components and systems to help manage vehicle performance and vehicle operations. Additionally, the HV battery may include one or more arrays of battery cells electrically interconnected between battery cell terminals and connector bus bars. The HV battery and its surroundings may include a thermal management system to help manage the temperature of the HV battery components, the HV battery systems, and the individual HV battery cells.The thermal management system may include a thermal insulation plate to allow coolant flow near the battery cells to assist in managing the thermal conditions of the battery cells.

[0003] DE 10 2009 005 124 A1 describes an electrical energy storage device with a plurality of storage cells, wherein several storage cells are stacked in a cell block and held together by a clamping device between two pressure plates, wherein the storage cells within the cell block are connected to one another in parallel and / or in series. Further prior art relating to the background of the invention is provided by JP 2014 203 621 A and JP 2006 244 755 A. SUMMARY

[0004] A traction battery assembly includes an array of plug-in battery cells, a pair of conductor supports, a pair of end plates, and first and second plates of spaced-apart bus bars. Each of the plug-in battery cells has terminal tabs extending from opposite side surfaces of the cells. The pair of conductor supports each extend along opposite sides of the array and are configured to have the terminal tabs pass therethrough. The pair of end plates are attached to the supports and arranged with them to hold the assembly therebetween. The first and second groupings of spaced-apart bus bars are each attached to a respective one of the supports such that the groupings are offset from one another and are arranged with adjacent terminal tabs to conductively connect the plug-in battery cells in series. At least one of the conductor supports can include a terminal post ora terminal conductively connected to the first and / or second grouping of spaced-apart busbars. The terminal post may be configured to electrically connect to another array of plug-in battery cells. The array may include an odd number of plug-in battery cells. Each of the pair of conductor supports may include a terminal post at opposite ends of the array configured to electrically connect the array to another array of plug-in battery cells. The array may include an even number of plug-in battery cells, and one of the pair of conductor supports may include two terminal posts at opposite ends of the array for electrically connecting the array to another array of plug-in battery cells.Clusters of adjacent plug-in battery cells may be connected in parallel, and the first and second groupings of spaced-apart bus bars may be arranged with the terminal tabs of the clusters to electrically connect the clusters in series. Each of the pair of conductor supports may define openings that are spaced apart from each other and configured to orient the terminal tabs with the respective first and second groupings of spaced-apart bus bars. One or more sense wires may be electrically connected to the plug-in battery cells and configured to measure the temperature, voltage, or current conditions of the array. Each of the bus bars may be electrically connected to at least two terminal tabs of opposite polarity or to a terminal post.

[0005] A vehicle includes an array of plug-in battery cells, a pair of carriers, and a plurality of bus bars. Each of the plug-in battery cells has terminal tabs of opposite polarity extending from opposite cell faces. The pair of carriers extend along the cell faces and each defines a plurality of openings sized to receive the terminal tabs. The plurality of bus bars are arranged with the carriers and with the terminal tabs such that electrical connection across the cells includes parallel and series connections. The plug-in battery cells may be arranged in clusters of adjacent cells connected in parallel, and the bus bars may be arranged in spaced-apart groups on each of the carriers and connected to adjacent terminal tabs to connect the clusters in series.One of the pair of carriers may include a terminal post at one end of the carrier that is conductively connected to the clusters of adjacent cells and configured to conductively connect to a different arrangement of battery cells. Each of the carriers may include a terminal post at opposite ends of the arrangement that is conductively connected to the clusters of adjacent cells and configured to conductively connect to a different arrangement of battery cells. Each of the busbars may define a tab opening to receive the terminal tab, and the tab opening may be aligned with one of the openings of the respective carrier. Further, the pair of carriers with the terminal tabs may be arranged to provide a gap for laser welding adjacent terminal tabs and busbars.

[0006] A traction battery assembly includes an array of plug-in battery cells, a pair of conductor supports, and a plurality of bus bars. The array of plug-in battery cells has terminal tabs extending from opposite side surfaces of the cells. The pair of conductor supports extend along opposite sides of the array and are each configured to retain the terminal tabs. The plurality of bus bars are mounted to the supports in a staggered configuration relative to each other and are configured to electrically connect parallel clusters of the cells in series with other parallel clusters of the cells. The pair of conductor supports may each include a terminal post conductively connected to the bus bars and configured to electrically connect to another array of plug-in battery cells.One of the pair of conductor supports may include a terminal post electrically connected to the bus bars and configured to electrically connect to another array of plug-in battery cells. One or more sense wires may be electrically connected to the plug-in battery cells and configured to measure temperature, voltage, and current conditions of the array. Each of the bus bars may define at least one opening for receiving one of the terminal tabs, and the opening may be substantially aligned with a carrier opening defined by one of the conductor supports. A pair of end plates may be attached to the supports at opposite ends of the array, and the end plates and the supports may be configured to be attached to a support structure of another support. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic diagram of a battery electric vehicle. Fig. 2 is a perspective view of an example of a portion of a traction battery. Fig. 3A is a perspective view of a plug-in battery cell assembly held between a pair of supports. Fig. 3B is a perspective view of a plug-in battery cell of the plug-in battery cell assembly of Fig. 3A. Fig. 4 is a perspective view of two clusters of battery cells of the plug-in battery cell assembly arranged with the pair of supports. Fig. Figure 5 is a perspective view of one of the pair of supports shown with a row of busbars attached thereto. Fig. 6 is a plan view of the plug-in battery cell assembly held between the pair of supports and a pair of end plates. DETAILED DESCRIPTION

[0007] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or reduced to show details of particular components. Thus, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art how to variously utilize embodiments of the present disclosure.As will be understood by one of ordinary skill in the art, various features illustrated and described with reference to one of the figures may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The combinations of illustrated features provide representative embodiments for typical applications. However, for particular applications or implementations, various combinations and modifications of the features may be desired in accordance with the teachings of this disclosure.

[0008] Fig. 1 shows a schematic diagram of a typical plug-in hybrid electric vehicle (PHEV). A typical plug-in hybrid electric vehicle 12 may include one or more electric machines 14 mechanically connected to a hybrid transmission 16. The electric machines 14 may operate as a motor or as a generator. Furthermore, the hybrid transmission 16 is mechanically connected to a prime mover 18. Furthermore, the hybrid transmission 16 is mechanically connected to a driveshaft 20, which is mechanically connected to the wheels 22. The electric machines 14 may provide propulsion and deceleration capability when the prime mover 18 is on or off. Furthermore, the electric machines 14 act as generators and may provide fuel economy benefits by recovering energy that would normally be lost as heat in the friction braking system.Additionally, since the hybrid electric vehicle 12 may be operated in an electric mode or a hybrid mode under certain conditions to reduce the overall fuel consumption of the vehicle 12, the electric work machines 14 may provide reduced pollutant emissions.

[0009] A traction battery or traction battery pack 24 stores and provides energy usable by the electric work machines 14. Typically, the traction battery 24 provides a high-voltage direct current output from one or more battery cell assemblies, sometimes referred to as battery cell stacks, within the traction battery 24. The battery cell assemblies may include one or more battery cells. The traction battery 24 is electrically connected to one or more power electronics modules 26 via one or more contactors (not shown). The one or more contactors disconnect the traction battery 24 from other components when opened and connect the traction battery 24 to other components when closed.The power electronics module 26 is also electrically connected to the electric machines 14 and provides the capability to bidirectionally transfer electrical power between the traction battery 24 and the electric machines 14. For example, a typical traction battery 24 may provide a DC voltage, while the electric machines 14 may require a three-phase AC voltage to operate. The power electronics module 26 may convert the DC voltage to a three-phase AC voltage when required by the electric machines 14. In a regenerative mode, the power electronics module 26 may convert the three-phase AC voltage from the electric machines 14, which act as generators, to the DC voltage required by the traction battery 24. The present description is equally applicable to a pure electric vehicle.For a pure electric vehicle, the hybrid transmission 16 may be a manual transmission connected to an electric work machine 14, and the prime mover 18 may not be present.

[0010] In addition to providing power for propulsion, the traction battery 24 can provide power to other vehicle electrical systems. A typical system may include a DC / DC converter module 28 that converts the high-voltage DC output of the traction battery 24 into a low-voltage DC supply compatible with other vehicle loads. Other high-voltage loads, such as compressors or electric heaters, may be directly connected to the high voltage without using a DC / DC converter module 28. In a typical vehicle, the low-voltage systems are electrically connected to an auxiliary battery 30 (e.g., a 12-volt battery).

[0011] An electrical battery control module (BECM) 33 may be in communication with the traction battery 24. The BECM 33 may act as a controller for the traction battery 24 and may also include an electronic monitoring system that manages the temperature and state of charge of each of the battery cells. The traction battery 24 may include a temperature sensor 31, such as a thermistor or other temperature measuring device. The temperature sensor 31 may be in communication with the BECM 33 to provide temperature data regarding the traction battery 24. Furthermore, the temperature sensor 31 may be located on or near the battery cells within the traction battery 24. It is also contemplated that more than one temperature sensor 31 may be used to monitor the temperature of the battery cells.

[0012] The vehicle 12 may, for example, be an electric vehicle such as a PHEV, an FHEV, an MHEV, or a BEV in which the traction battery 24 can be recharged by an external power source 36. The external power source 36 may be a connection to an electrical outlet. The external power source 36 may be electrically connected to an electric vehicle supply equipment (EVSE) 38. The EVSE 38 may provide circuitry and controls for regulating and managing the transfer of electrical energy between the power source 36 and the vehicle 12. The external power source 36 may provide DC or AC electrical power to the EVSE 38. The EVSE 38 may include a charging connector 40 for plugging into a charging port 34 of the vehicle 12. The charging port 34 may be any type of connector configured to transfer power from the EVSE 38 to the vehicle 12.The charging port 34 may be electrically connected to a charger or to an onboard power conversion module 32. The power conversion module 32 may condition the power supplied by the EVSE 38 to provide the proper voltage and current levels for the traction battery 24. The power conversion module 32 may interface with the EVSE 38 to coordinate the delivery of power to the vehicle 12. The EVSE connector 40 may have terminal pins that mate with corresponding recesses of the charging port 34.

[0013] The various components discussed may have one or more associated controllers to control and monitor their operation. The controllers may communicate via a serial bus (e.g., a Controller Area Network (CAN)) or via discrete conductors.

[0014] Battery cells, such as a prismatic cell, may contain electrochemical cells that convert stored chemical energy into electrical energy. Prismatic cells may contain a casing, a positive electrode (cathode), and a negative electrode (anode). An electrolyte may allow ions to move between the anode and cathode during discharge and then return during recharge. Terminals may allow current to flow from the cell for use by the vehicle. When positioned in a multiple battery cell array, the terminals of each battery cell may be oriented toward opposite terminals (positive and negative) that are adjacent to each other, and a bus bar may help enable series connection between the multiple battery cells.Additionally, the battery cells may be connected in parallel such that similar terminals (positive and positive, or negative and negative) are adjacent to each other. For example, two battery cells may be arranged with adjacent positive terminals, and the next two cells may be arranged with adjacent negative terminals. In this example, the bus bar may be in contact with the terminals of all four cells. The traction battery 24 may be heated and / or cooled using a liquid thermal management system, an air thermal management system, or other methods known in the art.

[0015] Compared to prismatic cells, plug-in battery cells may require different types of support structures to provide electrical connections within a plug-in battery cell assembly. For example, Fig. 2 shows an example of a portion of a traction battery, generally referred to herein as traction battery 100. The traction battery 100 may include an exo-support structure for holding a plug-in battery cell assembly 104 therein. The exo-support structure may include a floor 108, a pair of end plates 110, a pair of supports 112, and a cover 116. As shown in Fig. 3A, the plug-in battery cell assembly 104 may include a plurality of plug-in battery cells 120. As further shown in Fig. As shown in Figure 3B, each of the plug-in battery cells 120 may include a pair of outer side surfaces 122. Each of the plug-in battery cells 120 may include two terminal tabs 124 having opposite polarity. For each of the plug-in battery cells 120, one of the terminal tabs 124 having a positive polarity extends from one end of the outer side surfaces 122, and the other of the terminal tabs 124 having a negative polarity extends from the other of the outer side surfaces 122.

[0016] The traction battery 100 may include clusters of adjacent plug-in battery cells 120. For example, Fig. 3A illustrates the plug-in battery cell assembly 104 having a plurality of clusters of adjacent plug-in battery cells 120, such as cell clusters 150a and cell clusters 150b, which may be collectively referred to herein as cell clusters 150. In this example, each of the cell clusters 150 may include three plug-in battery cells 120, although it is contemplated that other examples of cell clusters 150 may include fewer or more than three plug-in battery cells 120. The supports 112 may help hold the plug-in battery cells 120 therebetween. For example, the supports 112 may extend along opposite sides of the plug-in battery cell assembly 104. The supports 112 may be attached to the floor 108, the pair of end plates 110, and the cover 116. The supports 112 may each define a plurality of openings 155 sized to receive the terminal tabs 124.The openings 155 may be spaced apart along the supports 112 to define a ladder shape of the supports 112. Each of the supports 112 may include a terminal post 156. The terminal post 156 may help transfer power from the plug-in battery cell assembly 104 to another vehicle battery component, such as another assembly of plug-in battery cells, a service disconnect point, an electrical work machine, a relay, or an electrical conductor of a battery.

[0017] For example, the Fig. 3A, Fig. 4 and Fig. 5 further shows the supports 112 with the conductor configuration. A series of busbars 160 may be mounted on an inner side of each of the supports 112. Each of the busbars 160 may define busbar openings sized to receive the terminal tabs 124. In this case, five busbars 160 are used, but it is contemplated that with other examples of traction batteries, more or fewer may be used in accordance with a number of battery cells. The busbars 160 may be sized and oriented with adjacent terminal tabs 124 to enable a conductive connection therebetween. The traction battery 100 may include a first and a second grouping of the busbars 160.Each of the arrays may be attached to one of the supports 112 such that the first array and the second array are offset relative to each other and are arranged with adjacent terminal tabs 124 to conductively connect the plug-in battery cells 120 in series. The bus bars 160, located at opposite ends of the supports 112, may include a terminal post flange 164. The terminal post flanges 164 may be arranged with the terminal posts 156 to help conductively connect the plug-in battery cell assembly 104 to other vehicle components, such as another plug-in battery cell assembly.

[0018] How to continue in Fig. As shown in Figure 6, the plug-in battery cells 120 of each cell cluster 150 may be arranged with the supports 112 and with the busbars 160 to enable electrical parallel connection and electrical series connection. For example, the busbars 160 of opposite supports 112 may be offset from each other to enable electrical parallel and series connection across the plug-in battery cell assembly 104. Fig.6 shows a top view of an example of the electrical parallel connection within each of the cell clusters 150 and the electrical series connection across the cell clusters 150. The plug-in battery cells 120 may be oriented within the respective cell cluster 150a or 150b such that terminal tabs 124 of the same polarity are adjacent to each other. The terminal tabs 124 of each of the respective cell clusters 150 may be welded to the respective bus bar 160. As mentioned above, the bus bars 160 of opposite supports 112 may be offset to enable electrical series connection of the cell clusters 150.In this example, the terminal posts 156 are both included on one of the carriers 112 because there is an even number of cell clusters 150, but it is contemplated that the terminal posts 156 may be located on different carriers 112 under certain conditions, such as a plug-in battery cell assembly containing an odd number of cell clusters 150.

[0019] Sensors may be included near the plug-in battery cells 120 to monitor their conditions. For example, one or more sense wires 168 may be attached to one of the carriers 112 and conductively connected to the plug-in battery cells 120 and / or to the busbars 160. In another example, conductive traces may be conductively connected to the plug-in battery cells 120 and / or to the busbars 160. The sense wires 168 may measure the conditions of the plug-in battery cell assembly 104, such as temperature, current, and voltage. The sense wires 168 may be in electrical communication with a controller, such as a BECM (not shown), to provide the measured conditions of the plug-in battery cell assembly 104 to the controller.

[0020] As described above, the supports 112 may be arranged with the bus bars 160 to help orient the plug-in battery cells 120 in both parallel and series. This arrangement provides advantages for extracting power from the plug-in battery cell assembly 104 for use within a vehicle. For example, connecting the plug-in battery cells 120 in parallel may provide increased current across the plug-in battery cell assembly 104, thereby increasing the power output of the plug-in battery cells 120. As another example, connecting the plug-in battery cells 120 in series may provide increased voltage across the plug-in battery cell assembly 104, thereby increasing the power output of the plug-in battery cells 120. In addition, the configuration may also provide advantages related to the assembly and installation of the traction battery 100.For example, the busbars 160 may define a substantially flat profile, which may assist in stamping the busbars 160 and accommodating laser welding during installation. As another example, the terminal post flanges 164 on the supports 112 may be shaped to accommodate packaging constraints. In yet another example, and as noted above, the terminal posts 156 may assist in conductively connecting the plug-in battery cell assembly 104 to other plug-in battery cell assemblies to provide traction battery configurations capable of drawing power from multiple sources.

[0021] Although various embodiments have been described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The terms used in the specification are terms of description rather than limitation, and it is to be understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the disclosure that may not be explicitly described or illustrated.Although various embodiments may have been described as offering advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, one of ordinary skill in the art will recognize that one or more features or characteristics may be included to achieve desired overall system attributes depending on the specific application and implementation. These attributes may include, but are not limited to, marketability, appearance, consistency, robustness, customer acceptance, reliability, accuracy, etc.Thus, embodiments described as being less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for certain applications.

Claims

[1] Traction battery assembly (24) comprising: an array (104) of plug-in battery cells (120) each having terminal tabs (124) extending from opposite side surfaces of the cells (120); a pair of conductor supports (112) each extending along opposite sides of the assembly (104) and configured to have the terminal tabs (124) pass therethrough; a pair of end plates (110) attached to the supports (112) and arranged with the supports (112) to hold the assembly (104) therebetween; and first and second groups of spaced-apart busbars (160), each of which is secured to one of the supports (112) in such a way that the groupings are offset from one another and are arranged with adjacent terminal tabs (124) in order to conductively connect the plug-in battery cells (120) in series. [2] The assembly (24) of claim 1, wherein at least one of the conductor supports (112) includes a terminal post (156) conductively connected to at least one of the first and second groupings of spaced-apart bus bars (160), and wherein the terminal post (156) is configured to electrically connect to another array (104) of plug-in battery cells (120). [3] The assembly (24) of claim 2, wherein the array (104) includes an odd number of plug-in battery cells (120), and wherein each of the pair of conductor supports (112) at opposite ends of the array (104) includes a terminal post (156) configured to electrically connect the array (104) to another array (104) of plug-in battery cells (120). [4] The assembly (24) of claim 2, wherein the array (104) includes an even number of plug-in battery cells (120) and wherein one of the pair of conductor supports (112) at opposite ends of the array (104) includes two terminal posts (156) for electrically connecting the array to another array (104) of plug-in battery cells. [5] The assembly (24) of any one of claims 1 to 4, wherein clusters (150) of adjacent plug-in battery cells (124) are connected in parallel, and wherein the first and second groupings of spaced-apart busbars (160) are arranged such that the terminal tabs (124) of the clusters (150) electrically connect the clusters (150) in series. [6] The assembly (24) of any one of claims 1 to 5, wherein each of the pair of conductor supports (112) defines openings (155) spaced apart from one another and configured to orient the terminal tabs (124) with the first and second groupings of spaced-apart bus bars (160), respectively. [7] The assembly (24) of any one of claims 1 to 6, further comprising one or more sense wires (168) electrically connected to the plug-in battery cells (120) and configured to measure the temperature, voltage, or current conditions of the array (104). [8] The assembly (24) of any one of claims 1 to 7, wherein each of the bus bars (160) is electrically connected to at least two terminal tabs (124) of opposite polarity or to a terminal post (156). [9] Vehicle (12) comprising: an array of plug-in battery cells (120) each having terminal tabs (124) of opposite polarity extending from opposite cell faces; a pair of supports (112) extending along the cell surfaces, each defining a plurality of openings (155) sized to receive the terminal tabs (124); and a plurality of busbars (160) arranged with the supports (112) and with the connecting tongues (124) in such a way that an electrical connection across the cells (120) includes parallel and series circuits. [10] The vehicle (12) of claim 9, wherein the plug-in battery cells (120) are arranged in clusters of adjacent cells (120) connected in parallel, and wherein the bus bars (160) are arranged in spaced-apart groups on each of the supports (112) and are connected to adjacent terminal tabs (124) to connect the clusters in series. [11] The vehicle (12) of claim 10, wherein one of the pair of supports (112) includes a terminal post (156) at both ends of the support (112) conductively connected to the clusters of adjacent cells (120) and configured to conductively connect to another array (104) of battery cells (120). [12] The vehicle (12) of claim 10, wherein each of the supports (112) at the opposite ends of the array (104) includes a terminal post (156) conductively connected to the clusters of adjacent cells (120) and configured to conductively connect to another array of battery cells (120). [13] The vehicle (12) of any one of claims 9 to 12, wherein each of the bus bars (160) defines a tongue opening for receiving the terminal tongue (124), and wherein the tongue opening is aligned with one of the openings (155) of the respective carrier (112). [14] The vehicle (12) of any one of claims 9 to 13, wherein the pair of supports (112) is further configured with the terminal tabs (124) to provide a gap for laser welding with adjacent terminal tabs (124) and bus bars (160). [15] Traction battery assembly comprising: an array of plug-in battery cells (120) each having terminal tabs (124) extending from opposite side surfaces of the cells (120); a pair of conductor supports (112) extending along opposite sides of the assembly (104), each configured to hold the terminal tabs (124); and a plurality of busbars (160) mounted to the supports (112) in a staggered configuration relative to one another and configured to electrically connect parallel clusters of the cells (120) in series with other parallel clusters of the cells (120). [16] The assembly of claim 15, wherein the pair of conductor supports (112) each includes a terminal post (156) conductively connected to the bus bars (160) and configured to electrically connect to another array (104) of plug-in battery cells (120). [17] The assembly of claim 15, wherein one of the pair of conductor supports (112) includes a terminal post (156) conductively connected to the bus bars (160) and configured to electrically connect to another array (104) of plug-in battery cells (120). [18] The assembly of any one of claims 15 to 17, further comprising one or more sense wires (168) electrically connected to the plug-in battery cells (120) and configured to measure temperature, voltage and current conditions of the array (104). [19] The assembly of any one of claims 15 to 18, wherein each of the bus bars (160) defines at least one opening for receiving one of the terminal tabs (124), and wherein the opening is substantially aligned with a support opening (155) defined by one of the conductor supports (112). [20] The assembly of any one of claims 15 to 19, further comprising a pair of end plates (110) secured to supports (112) at opposite ends of the assembly, the end plates (110) and supports (112) being configured to be secured to a support structure of another assembly (104).

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