Snap-in battery assembly

Abstract

Traction battery assembly (50) comprising: a support element (52); and a pair of adjacent cell rows (54) disposed on the support member (52), each row including a plurality of stacked cells (56) and a plurality of cell spacers (66) nested with the cells (56), and wherein a portion of each of the spacers (66) of one of the rows is inserted into one of the spacers (66) of the other row to form a plurality of continuously connected spacer pairs adapted to secure the rows together.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to traction battery assemblies for motor vehicles. BACKGROUND

[0002] Vehicles such as battery-electric vehicles (BEVs), plug-in hybrid-electric vehicles (PHEVs), or full hybrid-electric vehicles (FHEVs) contain a traction battery assembly that acts as a power source for the vehicle. The traction battery may contain components and systems to support the management of vehicle performance and operation. The traction battery may also contain high-voltage components.

[0003] US 2009 / 0 142 650 A1 describes a battery assembly in which a cooling passage is formed between battery cells consisting of a number of rectangular or prismatic cells, and in which gas is blown through the cooling passage by a fan. Further prior art relating to the background of the invention is provided by US 2008 / 0 160 395 A1, in which a battery assembly comprises a number of battery cells that can be arranged in series or parallel in a casing with insulating properties. BRIEF DESCRIPTION OF THE INVENTION

[0004] A traction battery assembly includes a support member and a pair of adjacent cell rows arranged on the support member. Each row contains a plurality of stacked cells and a plurality of cell spacers interleaved with the cells. A portion of each of the spacers from one of the rows is inserted into one of the spacers of the other row to form a plurality of continuously connected spacer pairs designed to secure the rows together.

[0005] A battery assembly includes a first row of cells with first cell spacers interleaved with the cells. Each of the first spacers includes a male connection feature. The battery assembly further includes a second row of cells adjacent to the first row and having second cell spacers interleaved with the cells. Each of the second spacers includes a female connection feature that receives the male feature of a corresponding one of the first spacers to secure the rows together.

[0006] A vehicle includes at least one electric machine configured to propel the vehicle and a traction battery assembly configured to supply power to the at least one electric machine. The battery assembly includes a support member and a pair of adjacent cell rows disposed on the support member. Each row has a plurality of stacked cells and a plurality of cell spacers interleaved with the cells. A portion of each of the spacers from one of the rows is inserted into one of the spacers of the other row to form a plurality of continuously connected spacer pairs configured to secure the rows together. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a schematic diagram of a typical plug-in hybrid electric vehicle (PHEV). Fig. 2 illustrates a perspective view of a battery assembly. Fig. 3 illustrates an exploded side view of a portion of the Fig. 2 shown battery assembly. Fig. 4 illustrates a front view of the Fig. 1 shown battery assembly. Fig. Figure 5 is a detailed view showing an exemplary connection between a pair of cell spacers. DETAILED DESCRIPTION

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

[0008] Fig. 1 shows a schematic representation of a typical plug-in hybrid electric vehicle (PHEV). However, certain embodiments may also be implemented within the context of non-plug-in hybrids and fully electric vehicles. The vehicle 12 may include one or more electric machines 14 mechanically connected to a hybrid transmission 16. The electric machines 14 may be capable of operating as a motor or as a generator. Additionally, the hybrid transmission 16 may be mechanically connected to an internal combustion engine 18. The hybrid transmission 16 may also be 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 internal combustion engine 18 is on or off.The electric machines 14 also function as generators and can provide fuel economy benefits by recovering energy through regenerative braking. The electric machines 14 reduce polluting emissions and increase fuel economy by reducing the workload of the internal combustion engine 18.

[0009] A traction battery or battery pack 24 stores energy that can be used by the electric machines 14. The traction battery 24 typically provides a high-voltage direct current output from one or more battery cell strings within the traction battery 24, sometimes referred to as battery cell stacks. The battery cell strings may include one or more battery cells.

[0010] The battery cells, such as a prismatic or pouch cell, may contain electrochemical cells that convert stored chemical energy into electrical energy. The 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 recharging. Terminals may allow current to flow out of the cell for use by the vehicle. When positioned in an array with multiple battery cells, the terminals of each battery cell may be aligned with opposite terminals (plus and minus) that are adjacent to each other, and a bus bar may help enable series connection between the multiple battery cells.The battery cells can also be arranged in parallel so that similar connections (plus and plus or minus and minus) are adjacent to each other.

[0011] Different battery pack configurations may be available to address individual vehicle variables, including packaging constraints and power requirements. The battery cells can be thermally controlled using a thermal management system. Examples of thermal management systems may include air-cooled systems, liquid-cooled systems, and a combination of air and liquid systems.

[0012] The traction battery 24 may be electrically connected to one or more power electronics modules 26 through one or more contactors (not shown). The one or more contactors disconnect the traction battery 24 from other components when open and connect the traction battery 24 to other components when closed. The power electronics module 26 may be electrically connected to the electric machines 14 and provides the capability for bidirectional transfer of 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 function. The power electronics module 26 may convert the DC voltage to a three-phase AC voltage as required by the electric machines 14.In a regenerative mode, the power electronics module 26 can convert the three-phase AC voltage from the electric machines 14, which act as generators, into the DC voltage required by the traction battery 24. The description herein is equally applicable to a pure electric vehicle. In a pure electric vehicle, the hybrid transmission 16 may be a transmission connected to an electric machine 14, and the internal combustion engine 18 may not be present.

[0013] 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 and electric heaters, may be directly connected to the high voltage without the use of 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).

[0014] A battery electrical control module (BECM) 33 may be in communication with the traction battery 24. The BECM 33 may function as a controller for the traction battery 24 and may also include an electronic monitoring system that manages the temperature and state of charge for 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.

[0015] The vehicle 12 can be recharged from an external power source 36. The external power source 36 is a connection to an electrical outlet. The external power source 36 can be electrically connected to an electric vehicle supply equipment (EVSE) 38. The EVSE 38 can 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 can provide DC or AC electrical power to the EVSE 38. The EVSE 38 can include a charging connector 40 for plugging into a charging port 34 of the vehicle 12. The charging port 34 can be any type of port configured to transfer power from the EVSE 38 to the vehicle 12. The charging port 34 can be electrically connected to a charger or an onboard power conversion module 32.The power conversion module 32 may condition the power supplied from the EVSE 38 to provide the proper voltage and current levels to the traction battery 24. The power conversion module 32 may be coupled to the EVSE 38 to coordinate the delivery of power to the vehicle 12. The EVSE connector 40 may have pins that mate with corresponding recesses of the charging port 34.

[0016] The various components discussed may have one or more linked controllers to control and monitor their operation. The controllers may be connected via a serial bus (e.g., Controller Area Network (CAN)) or via dedicated electrical wiring.

[0017] The Fig.2 through 5 and the related discussion describe examples of the traction battery assembly 24. The traction battery assembly 50 includes a support member 52 that supports at least one battery string 54. For example, the support member 52 may support a pair of adjacent battery strings 54. The at least one battery string 54 includes a plurality of stacked battery cells 56. Each cell 56 may be a pouch cell having at least one terminal 58 extending from at least one side of the cell 56. Alternatively, each cell may be a prismatic cell or a cylindrical cell. Each cell 56 may have opposing major sides 60 and opposite ends 64 extending between the major sides 60. The cells 56 are stacked such that at least one of the major sides 60 of a cell faces a major side of at least one other cell.The opposite ends 64 collectively define opposite longitudinal sides of the row 54. If there is more than one row, the rows 54 may be positioned on the support member 52 with one of the longitudinal sides of one row adjacent to one of the longitudinal sides of another row.

[0018] Each of the rows 54 may include a plurality of cell spacers 66 nested with the cells 56. Each row 54 may be arranged so that each cell 56 has one cell spacer 66 or arranged so that there is one cell spacer 66 for every two cells 56. Each cell spacer 66 may have opposite major sides 68 and opposite ends 70 extending between the opposite major sides. Each cell spacer 66 may also include a top portion 72 having a roof surface 74, a cantilevered front portion 76, and a cantilevered rear portion 80. The cantilevered portions 76, 94 extend beyond the major sides 68, generally forming a T-shape when viewed from either end. The cantilevered front portion 76 may include a front contact surface 78, and the cantilevered rear portion 80 may include a rear contact surface 82.The front contact surface 78 of one of the spacers engages the rear contact surface 82 of an adjacent spacer 66 when the row 54 is assembled. Each of the front contact surfaces 78 may include at least one protrusion 98. Each of the rear contact surfaces 82 may include at least one receptacle 100 configured to receive a corresponding protrusion 98. The protrusion 98 and the receptacle 100 cooperate to snap adjacent spacers 66 together. The protrusion 98 may include barb-like features that cooperate with the corresponding geometries in the receptacle 100 to prevent the protrusion 98 from being withdrawn from the receptacle 100. The protrusions may be removable from the receptacles for servicing using sufficient force.

[0019] Each spacer 66 may also include a lower portion 86 having a bottom surface 88, a cantilevered front portion 90, and a cantilevered rear portion 94. The cantilevered front portion 90 may include a front contact surface 92, and the cantilevered rear portion 94 may include a rear contact surface 96. The front contact surface 92 of one of the spacers 66 may snap into place with the rear contact surface 96 of an adjacent spacer 66 when the row 54 is assembled. Each of the front contact surfaces 92 may include at least one projection 102. Each of the rear contact surfaces 96 may include at least one receptacle 104 configured to receive a corresponding projection 102. The projection 102 and the receptacle 104 cooperate to snap adjacent spacers 66 together.

[0020] The projection 102 may include barb-like features that cooperate with the corresponding geometries in the receptacle 104 to prevent the projection 102 from being withdrawn from the receptacle 104.

[0021] Each spacer 66 may include a front pocket 106 indented into one of the main sides 68 and may include a rear pocket 114 indented into the other main side 68. Each pocket may include an inner surface 108 and a bottom and top surface 110, 112. The front pocket and the rear pocket 106 may each receive at least a portion of one of the cells 56 therein. The cells may be received such that one of the main sides 60 of the cell is disposed against the inner surface 108, and such that the roof of the cell 122 is disposed against the top surface 110, and the bottom of the cell 124 is disposed against the bottom surface 112. The spacer 66 may also include terminal slots 84 through which the terminals 58 pass.The terminal slots 84 allow the terminal 58 to extend outwardly of the cell spacer 66 so that the terminals 58 can be electrically connected to one another. Each spacer 66 may also include at least one male connection feature 126 extending perpendicularly from one of the opposite ends 70. The other opposite end 70 may define at least one female connection feature 128. The male connection feature 126 may also be referred to as a protrusion. The female connection feature 128 may also be referred to as a receptacle. The specific type of attachment feature may vary depending on the cell type, cell material, and other design considerations.

[0022] The traction battery assembly 50 may first be assembled by assembling the cells 56 and the spacers 66 into individual modular rows 54. Each row 54 may then be attached to other rows. The rows 54 may be attached to one another by connecting the female and male connection features on each of the spacers 66. For example, the traction battery assembly 50 may include a first row 150 and a second row 152. Each of the male connection features 126 of the first row 150 may snap into the female connection features 128 of the second row 152, forming a plurality of continuously connected spacer pairs configured to secure the rows together. The cells and spacers of each of the rows 150, 152 may be arranged such that both rows are identical.

[0023] For each spacer pair, the at least one male connection feature 126 may include a neck 154 and a head 156 disposed at a distal end of the neck. A proximal end of the neck 154 is connected to one of the opposite ends 70 of the spacer 66 and projects outwardly from the end 70 in a substantially perpendicular direction. The head 156 has a larger base area than the neck 154 and includes a barb 158. The neck 154 and the head 156 may be integral. The male connection feature 126 may be integral with the spacer 66.

[0024] For each spacer pair, at least one female connecting feature 128 may include a receptacle 160 engaged with one of the opposite ends 70 of the spacer 66. The receptacle 160 may include a main portion 162 and an entrance portion 164 opening into the end 70 and providing a path for objects to be received within the main portion 162. When connected, the male connecting feature 126 is disposed within the female connecting feature 128 with the neck 154 disposed largely within the entrance portion 164 and with the head 156 disposed within the main portion 162. The head 154 includes a tapered surface 166 that assists the head in penetrating the entrance portion 164. The neck 154 may also include some degree of flexibility to allow the head 156 to translate as it penetrates the entrance portion 164.Once the head 156 is received within the main body 162, the barb 158 cooperates with a latch wall 168 to prevent the male connecting feature 126 from disengaging from the female connecting feature 128. Both connecting features may be designed with a degree of flexibility to allow the connecting features to disengage from each other when sufficient force is applied.

[0025] After the first and second rows are connected together, the rows 150, 152 may be connected to the support member 52. The rows may be connected to the support member using male and female connection features similar to those described above. For example, the support member 52 may include a pair of opposing longitudinal sidewalls 180, 182 extending upwardly from a support member base 184. The support member 52 may also include opposing front and rear walls 186 extending between the longitudinal sidewalls to define an open cavity 188 surrounding the rows. The longitudinal sidewalls 180 may include a plurality of male connection features 190 extending outwardly from an inner surface of the sidewall 180. The male connection features 190 are registered with the female connection features 128 of the spacers 66 of the first row 150.Each male connection feature 190 engages a corresponding female connection feature 128 to secure the rows to the support member 52. The male connection feature 190 may be similar to the male connection feature 126 and may be attached to the female connection feature 128 in a manner similar to how the male connection feature 126 engages the female connection feature 128.

[0026] The longitudinal sidewall 182 may include a plurality of female connection features 192 indented into the longitudinal sidewall 182. The female connection features 192 are registered with the male connection features 126 of the second row spacers 152. Each male connection feature 126 engages a corresponding female connection feature 192 to secure the rows to the support member 52. The female connection feature 192 may be similar to the female connection feature 128 and may engage the male connection feature 126 in a similar manner to how the female connection feature 128 engages the male connection feature 126. Additional brackets 194 may be used to further secure the rows to the support member 52. Each bracket 194 may be connected between the front and rear walls 186.A lower surface of each bracket is disposed against a roof of the row to secure the rows to the support member base 184.

[0027] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The terms used in the specification are for the purpose of description rather than limitation, and it is 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 invention that may not be explicitly described or illustrated.While various embodiments may have been described as offering advantages or being preferred over other prior art embodiments or implementations with respect to one or more desired characteristics, as those of ordinary skill in the art will recognize, compromises may be made with respect to one or more features or characteristics to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc.Thus, embodiments that are described as less desirable than other prior art embodiments or 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 (50) comprising: a support element (52); and a pair of adjacent cell rows (54) disposed on the support member (52), each row including a plurality of stacked cells (56) and a plurality of cell spacers (66) nested with the cells (56), and a portion of each of the spacers (66) of one of the rows being inserted into one of the spacers (66) of the other row to form a plurality of continuously connected spacer pairs adapted to secure the rows together. [2] The traction battery assembly (50) of claim 1, wherein each of the spacers (66) includes a projection (98) or a receptacle (100), and wherein the projection (98) of one of the spacers (66) is received within the receptacle (100) of an adjacent one of the spacers (66). [3] The traction battery (50) of claim 1 or 2, wherein the support member (52) further includes at least one standing wall having a plurality of receptacles (100) registered with the spacer pairs, and wherein each of the spacer pairs further includes at least one projection (98) configured to be received within one of the plurality of receptacles (100) to secure the rows to the support member (52). [4] Traction battery (50) according to one of claims 1 to 3, wherein the support member (52) further includes at least one standing wall having a plurality of projections (98) registered with the spacer pairs, and wherein each of the spacer pairs further includes a receptacle (100) adapted to receive one of the plurality of projections (98) to secure the rows to the support member (52). [5] A traction battery (50) according to any one of claims 1 to 4, wherein each of the cell spacers defines opposing pockets each adapted to receive at least a portion of one of the cells (56). [6] The traction battery (50) of any one of claims 1 to 5, further comprising each of the plurality of spacer pairs comprising a first cell spacer (66) having a male connection feature (126) and a second cell spacer (66) having a female connection feature (128) configured to receive the male connection feature (126) therein. [7] Vehicle (12) comprising: at least one electric machine (14) designed to drive the vehicle (12); and a traction battery assembly (50) configured to supply power to the at least one electric machine (14), the battery assembly (50) including a support member (52) and a pair of adjacent cell rows (54) disposed on the support member (52), each row (54) having a plurality of stacked cells (56) and a plurality of cell spacers (66) interleaved with the cells (56), and a portion of each of the spacers (66) from one of the rows being inserted into one of the spacers (66) of the other row to form a plurality of continuously connected spacer pairs configured to secure the rows (54) together. [8] The vehicle (12) of claim 7, wherein each of the spacers (66) includes a projection (98) or a receptacle (100), and wherein the projection (98) of one of the spacers (66) is received within the receptacle (100) of an adjacent one of the spacers (66). [9] The vehicle (12) of claim 7 or 8, further wherein each of the plurality of spacer pairs includes a first cell spacer (66) having a male connection feature (126) and a second cell spacer (66) having a female connection feature (128) configured to receive the male connection feature (126) therein. [10] The vehicle (12) of any one of claims 7 to 9, wherein the support member (52) further includes at least one upright wall having a plurality of receptacles (100) registered with the spacer pairs, and wherein each of the spacer pairs further includes at least one projection (98) configured to be received within one of the plurality of receptacles (100) to secure the rows (54) to the support member (52).

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