Battery pack with integrated cooling system

Abstract

A battery pack comprises a first head section with a first conduit and a second head section with a second conduit. The battery pack also includes an energy storage system with energy storage cells located between the first and second head sections. A coolant plate assembly is located between the first and second head sections and is adjacent to the multitude of energy storage cells. The coolant plate assembly includes a coolant channel with a first end fluidically connected to the first conduit, a second end fluidically connected to the second conduit, and an intermediate section defining a flow path. The coolant plate assembly also includes a first planar section with a first surface facing the energy storage cells and a second surface with projections extending into the coolant channel.

Description

[0001] The subject matter of the disclosure relates to rechargeable energy storage systems and, more particularly, to a rechargeable energy storage system for a vehicle comprising a battery pack with an integrated cooling system.

[0002] Rechargeable energy storage systems (RESS) typically comprise one or more battery packs with rechargeable energy storage cells. The battery pack can be connected to an external charging system, which recharges the electrical energy lost to a load. The charging system can be part of a vehicle or part of an external charging station. When powering a vehicle, the battery pack discharges the stored electrical energy. The charging and discharging of the stored electrical energy generates heat, which, if not dissipated, can impair the efficiency of the battery pack.

[0003] There are a variety of systems used to cool batteries. For example, many batteries have a forced air convection system that directs an airflow over the battery components. Other systems may use heat sinks to absorb heat. The absorbed heat can be dissipated into the forced airflow. Still other systems may use cold plates. A cold plate is typically made of aluminum and may include internal channels through which a fluid circulates. The fluid absorbs the heat that may be dissipated by a battery pack in thermal contact with the cold plate. Description

[0004] A battery pack is described herein. The battery pack includes a first header having a first conduit and a second header having a second conduit. The battery pack also includes an energy storage system having energy storage cells disposed between the first and second headers. A coolant plate assembly is disposed between the first header and the second header and adjacent to the plurality of energy storage cells. The coolant plate assembly includes a coolant channel having a first end fluidly connected to the first conduit, a second end fluidly connected to the second conduit, and an intermediate portion defining a flow path. The coolant plate assembly also includes a first planar portion having a first surface facing the energy storage cells and a second surface having protrusions extending into the coolant channel.

[0005] Another aspect of the disclosure may be that the first plurality of protrusions comprise different heights relative to the second surface of the first planar portion.

[0006] Another aspect of the disclosure may be that the first plurality of protrusions are arranged in rows, wherein the first plurality of protrusions in adjacent rows are offset relative to each other in a direction perpendicular to a direction of coolant flow through the coolant channel.

[0007] Another aspect of the disclosure includes another group of energy storage cells disposed between the first header and the second header and spaced from the energy storage cells. Another coolant plate assembly is disposed between the first header and the second header and adjacent to each of the other groups of energy storage cells. The another coolant plate includes another coolant channel having a first end portion fluidly connected to the first conduit, a second end portion fluidly connected to the second conduit, and an intermediate portion defining another flow path. The another coolant plate assembly includes a second planar portion having a first surface facing the other group of energy storage cells and a second surface having second protrusions extending into the other coolant channel.

[0008] Another aspect of the disclosure may be that the second plurality of protrusions comprise different heights relative to the second surface.

[0009] Another aspect of the disclosure may be that the second plurality of protrusions are arranged in rows, wherein the second plurality of protrusions in adjacent rows are offset relative to each other in a direction perpendicular to the coolant flow through the other coolant channel.

[0010] Another aspect of the disclosure may be that the first surface on the first planar portion of the coolant plate assembly is coated with a thermal compound that directly contacts the plurality of energy storage cells, and that the first surface on the second planar portion of the other coolant plate is coated with a thermal compound that directly contacts the other plurality of energy storage cells.

[0011] Another aspect of the disclosure may be that the coolant plate assembly comprises a first curved portion having a first inner surface facing the coolant channel and a first outer surface, and the further coolant plate assembly comprises a second curved portion having a second inner surface facing the other coolant channel and a second outer surface.

[0012] Another aspect of the disclosure may be that the first outer surface of the coolant plate assembly is adjacent to the second outer surface of the other coolant plate assembly at a cooling plate interface.

[0013] Another aspect of the disclosure may include a first air gap disposed on a first side of the cold plate interface and a second air gap disposed on a second side of the cold plate interface.

[0014] Another aspect of the disclosure may be that the first plurality of protrusions each comprise a peripheral wall extending from the first surface of the first planar portion to a first outwardly facing surface, and that the second plurality of protrusions each comprise a peripheral wall extending from the second surface of the second planar portion to an outwardly facing surface.

[0015] Another aspect of the disclosure may be that the first conduit comprises a first coolant inlet conduit and a first coolant outlet conduit, and the second conduit comprises a second coolant inlet conduit and a second coolant outlet conduit, wherein the first coolant inlet conduit is fluidly connected to the second coolant outlet conduit and the second coolant inlet conduit is fluidly connected to the first coolant outlet conduit.

[0016] A vehicle is disclosed herein. The vehicle includes a body defining a passenger compartment, an electric motor mounted in the body, and a battery pack connected to the electric motor. The battery pack includes a first header having a first conduit and a second header having a second conduit. The battery pack further includes an energy storage system having energy storage cells disposed between the first header and the second header. A coolant plate assembly is disposed between the first header and the second header and is adjacent to the plurality of energy storage cells. The coolant plate assembly includes a coolant channel having a first end fluidly connected to the first conduit, a second end fluidly connected to the second conduit, and an intermediate portion defining a flow path.The coolant plate assembly also includes a first planar portion having a first surface facing the energy storage cells and a second surface having protrusions extending into the coolant channel.

[0017] A coolant system is disclosed herein. The coolant system includes a coolant plate assembly disposed between a first header and a second header. The coolant plate assembly includes a coolant channel having a first end fluidly connected to a first conduit, a second end fluidly connected to a second conduit, and an intermediate portion defining a flow path. The coolant plate assembly also includes a first planar portion having a first surface facing at least a first energy storage cell and a second surface at least partially defining the cooling channel and having a first set of protrusions extending into the cooling channel. The cooling system also includes another cooling plate assembly disposed between the first header and the second header.The further coolant plate assembly comprises a further coolant channel having a first end portion fluidly connected to the first conduit, a second end portion fluidly connected to the second conduit, and an intermediate portion defining a further flow path. The further coolant plate also comprises a second planar portion having a first surface facing the at least one second energy storage cell and a second surface having a second group of protrusions extending into the further coolant channel. Short description of the drawings

[0018] Further features, advantages and details are included only as examples in the following detailed description, which refers to the drawings in which they are shown: Fig. 1 is a left side view of a vehicle with a rechargeable energy storage system including a battery pack with an integrated cooling system, according to one non-limiting example; Fig. 2 is a schematic view of a portion of a battery pack having a first plurality of cells and a second plurality of cells separated by a first cold plate and a second cold plate, according to a non-limiting example. Fig. 3 is a disassembled view of the first plurality of cells and second plurality of cells and the first and second cold plates according to a non-limiting example. Fig. 4 is an end elevational view of one of the first plurality of cells and one of the second plurality of cells and the first and second coolant plates of Fig. 3, comprising an amount of coolant liquid, according to a non-limiting example. Fig. 5 is a perspective view of the first coolant plate in an expanded view according to a non-limiting example. Fig. 6 is a side elevation view of a first planar portion having a plurality of aligned protrusions according to a non-limiting example. Fig. 7 is a side elevation view of a first planar portion having a plurality of offset protrusions according to a non-limiting example. Fig. 8 is a schematic end elevation view of another first coolant plate assembly and a second coolant plate assembly having equal height protrusions, according to a non-limiting example. Fig. 9 is a schematic end elevation view of yet another first coolant plate assembly and a second coolant plate assembly having different height protrusions according to a non-limiting example. Fig. 10 is a schematic view of the formation of a first planar portion of either the first coolant plate assembly or the second coolant plate assembly according to a non-limiting example. Fig. 11 is a schematic view of the attachment of the Fig. 10 formed first planar portion on an energy storage cell according to a non-limiting example. Detailed description

[0019] The following description is merely exemplary and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference characters designate like or corresponding parts and features.

[0020] A vehicle according to a non-limiting example is in Fig. 1, generally designated 10. The vehicle 10 includes a body 12 supported on a plurality of wheels 16. One or more of the plurality of wheels 16 are steerable. The body 12 partially defines a passenger compartment 20 with seats 23 disposed behind an instrument panel 26. A steering controller 30 is disposed between the seats 23 and the instrument panel 26. The steering controller 30 is actuated to control the orientation of the steerable wheel(s).

[0021] The vehicle 10 includes an electric motor 34 connected to a transmission 36 and supplying power to one or more of the wheels 16. A rechargeable energy storage system (RESS) 38 is disposed within the body 12 and supplies power to the electric motor 34. It should be noted that the arrangement of the electric motor 34, the transmission 36, and the RESS 38 within the body 12 may vary. Referring to Fig. 2 and Fig. 3, the RESS 38 includes a battery pack 40 with an energy storage system generally designated 42.

[0022] The energy storage system 42 is arranged between a first header 44 and a second header 46. The first header 44 includes a first interior space 48, and the second header 46 includes a second interior space 50. In the non-limiting example shown, the energy storage system 42 includes a first energy storage cell row 51 and a second energy storage cell row 52 arranged adjacent to and parallel to the first energy storage cell row 51. Although two energy storage cell rows 51, 52 are referred to, the number and arrangement of the energy storage cell rows arranged between the first header 44 and the second header 46 can vary.

[0023] The first energy storage cell row 51 comprises a first plurality of energy storage cells 54 and the second energy storage cell row 52 comprises a second plurality of energy storage cells 55. The first plurality of energy storage cells 54 comprises a first energy storage cell 56, a second energy storage cell 57, a third energy storage cell 58 and a fourth energy storage cell 59. The second plurality of energy storage cells 55 comprises a fifth energy storage cell 62, a sixth energy storage cell 63, a seventh energy storage cell 64 and an eighth energy storage cell 65. The number of cells in each energy storage cell row can vary.

[0024] This is followed by reference to the Fig. 3 and Fig. 4 with continued reference to Fig. 2 to describe the first energy storage cell 56 and the fifth energy storage cell 62, it being assumed that the remaining energy storage cells 57-59 and 63-65 comprise a similar structure. In one non-limiting example, the first energy storage cell 56 comprises a first surface 67, a second surface 69 generally parallel to the first surface 67, a third surface 71 extending between the first surface 67 and the second surface 69, and a fourth surface 73 generally parallel to the third surface 71. The first energy storage cell 56 comprises further surfaces (not separately labeled). Electrical connection elements, shown in the form of an anode 75 and a cathode 77, are arranged on the third surface 71.

[0025] The fifth energy storage cell 62 includes a first surface portion 80, a second surface portion 82 generally parallel to the first surface portion 80, a third surface portion 84 extending between the first surface portion 80 and the second surface portion 82, and a fourth surface portion 86 generally parallel to the third surface portion 84. The fifth energy storage cell 62 includes additional surfaces (not separately labeled). Electrical connection elements, shown in the form of an anode element 88 and a cathode element 90, are disposed on the third surface portion 84.

[0026] In one non-limiting example, the battery pack 40 includes a first coolant plate assembly 93 disposed on the second surface 69 of each of the first plurality of energy storage cells 54, and a second coolant plate assembly 95 disposed on the first surface portion 80 of each of the second plurality of energy storage cells 55. In one non-limiting example, the first coolant plate assembly 93 and the second coolant plate assembly 95 are adjacent to each other and are disposed between adjacent rows of energy storage cells, as shown in Fig. 2 shown.

[0027] In a non-limiting example, set out in the Fig. 3-5, the first coolant plate assembly 93 includes a first planar portion 99 and a first curved portion 102, which together at least partially define a first coolant channel 104. The first planar portion 99 includes a first surface 99A facing and secured relative to each of the first plurality of energy storage cells 54, and a second surface 99B opposite the first surface 99A and at least partially defining the first coolant channel 104. The first surface 99A can be directly secured to the first plurality of energy storage cells 54 via a first adhesive element 103 ( Fig. 4). The first curved portion 102 includes an inner surface 102A facing the first coolant channel 104 and an outer surface 102B facing away from the first coolant channel 104. The first coolant channel 104 extends between a first end 106 disposed on the first head portion 44 and a second end 108 disposed on the second head portion 46.

[0028] In one non-limiting example, the second coolant plate assembly 95 includes a second planar portion 112 and a second curved portion 114 that together at least partially define a second coolant channel 116. The second planar portion 112 includes a first surface 112A facing and secured relative to each of the second plurality of energy storage cells 55, and a second surface 112B opposite the first surface 112A and at least partially defining the second coolant channel 116. The first surface 112A may be directly secured to the second plurality of energy storage cells 55 by a second adhesive member 115. The second curved portion 114 includes an inner surface 114A facing the second coolant channel 116 and an outer surface 114B facing away from the second coolant channel 116.The outer surface 114B of the second coolant plate assembly 95 is adjacent to the outer surface 102B of the first coolant plate assembly 93 at an interface. The second coolant channel 116 extends between a first end portion 118 disposed on the first head portion 44 and a second end portion 120 disposed on the second head portion 46.

[0029] In a non-limiting example, Fig. 2, a first coolant inlet conduit 122 extends through the first header 44 and is fluidly connected to the first coolant channel 104 at the first end 106. A first coolant outlet conduit 123 extends through the first header 44 and is fluidly connected to the second coolant channel 116 at the first end portion 118. At this point, it should be clear that the first coolant inlet conduit 122 and the first coolant outlet conduit 123 are connected to coolant channels (not separately labeled) that extend through the remaining first and second coolant plates.

[0030] As in Fig. 2, a second coolant inlet conduit 124 extends through the second header 46 and is fluidly connected to the second coolant channel 116 at the second end portion 120. A second coolant outlet conduit 125 extends through the second header 46 and is fluidly connected to the second end 108 of the first coolant channel 104. The particular arrangement of the coolant inlet conduits 122 and 124 and the coolant outlet conduits 123 and 125 creates crossflow between the adjacent energy storage cell rows 51 and 52. The crossflow improves the efficiency of heat exchange between the coolant flowing through the first coolant channel 104 and the second coolant channel 116 and the first and second pluralities of energy storage cells 54 and 55.

[0031] It should be noted that the coolant flowing through the first coolant plate assembly 93 and the second coolant plate assembly 95 may be driven by a pump (not shown) and passed through a heat exchanger (also not shown). The first and second coolant inlet lines 122 and 124 are fluidly connected by a coolant supply line 126, which in turn is fluidly connected to the pump (not shown), and the first coolant outlet line 123 and the second coolant outlet line 125 may conduct heat via the entrained fluid through a coolant outlet line 127 and further into the heat exchanger (also not shown).

[0032] As in Fig. 4, a first coolant 128 flows through the first coolant channel 104, and a second coolant 129 flows through the second coolant channel 116. The specific type of coolant may vary and could include liquid coolants such as water solutions, glycol solutions, and the like, as well as gaseous coolants. In addition to the coolant, air may flow through the gaps 130 formed between the outer surfaces 102B and 114B of the first and second coolant plate assemblies 93, 95, respectively. The air may be forced convection air currents directed across the battery pack 40.

[0033] Furthermore, the gaps 130 between the first coolant plate assembly 93 and the second coolant plate assembly 95 can accommodate a degree of compression resulting from the operation of the battery pack 40 by allowing a degree of deformation of, for example, the first curved portion 102 and / or the second curved portion 114. The amount of deformation of the first curved portion 102 and / or the second curved portion 114 can be between about 0.1 mm and about 2 mm.

[0034] As in the Fig. 4-7, the first coolant plate assembly 93 includes a first plurality of protrusions 117 extending in a direction away from the first energy storage cells 54 and into the first cooling channel 104. Similarly, the second coolant plate assembly 95 includes a second plurality of protrusions 119 extending in a direction away from the second plurality of energy storage cells 55 and into the second coolant channel 116. In the example shown, the first and second pluralities of protrusions 117, 119 are arranged in rows extending perpendicular to a direction of coolant flow through the first and second coolant channels 104, 116, respectively.

[0035] As in the Fig. 6 and Fig. 7, the projections 117 on the first planar portion 99 may have different arrangements depending on the degree of local turbulence to be generated in the coolant flow. Fig. 6 and Fig. 7, the first planar section 99 is shown, but the illustrated arrangement of the protrusions 117 also applies to the protrusions 119 on the second planar section 112 of the second coolant plate assembly 95. In one example, the protrusions 117 have a vertical distance D1 between two adjacent protrusions 117 that is less than five times an equivalent diameter D0 of the protrusions 117. In this example, the vertical lies in a direction perpendicular to the coolant flow F through the first channel 104. In addition, the horizontal distance D2 between adjacent protrusions 117 should be less than ten times the equivalent diameter D0 of the protrusions 117 in order to increase the local turbulence in the coolant flow F and improve heat transfer. Furthermore, the protrusions 117 can be arranged in a grid of aligned rows and rows, as in Fig. 7, or the first plurality of projections 117 may be arranged in rows, with adjacent rows offset relative to each other in a direction perpendicular to the coolant flow F through the first coolant channel 104.

[0036] Fig. 8 shows the first coolant plate assembly 93 and second coolant plate assembly 95 with another example set of the first and second plurality of protrusions 117-1 and 119-1, respectively. The first and second plurality of protrusions 117-1 and 119-1 are similar to the first and second plurality of protrusions 117 and 119 disclosed above; differences apparent from the drawings are described below. In the illustrated example, the first and second plurality of protrusions 117-1, 119-1 include a varying spacing between adjacent protrusions 117-1, 119-1 in a direction perpendicular to a flow direction of coolant flow through the first and second coolant channels 104, 116 in the first and second coolant plate assemblies 93, 95, respectively.In particular, a distance between the first and second plurality of protrusions 117-1, 119-1 in a central region of a column of the first and second coolant channels 104, 116 is less than a distance between adjacent first and second protrusions 117-1, 119-1 along the edges of the first and second coolant channels 104, 116, respectively. A feature of the variable distance is the increased heat transfer due to different turbulences that arise in the coolant flow in the first and second coolant channels 104, 116.

[0037] Fig. 9 shows the first and second coolant plate assemblies 93, 95 with another example set of the first and second plurality of protrusions 117S-2, 117T-2, 119S-2, 119T-2. The first and second plurality of protrusions 117S-2, 117T-2, 119S-2, 119T-2 are similar to the first and second plurality of protrusions 117 and 119 disclosed above. Differences apparent from the drawings are described below. In the example shown, the first and second plurality of protrusions 117S-2, 117T-2, 119S-2, 119T-2 include a varying distance between adjacent protrusions 117S-2, 117T-2, 119S-2, 119T-2 in a direction perpendicular to a direction of coolant flow through the first and second coolant channels 104, 116 in the first and second coolant plate assemblies 93, 95, respectively. In addition, the first and second plurality of protrusions 117S-2, 117T-2, 119S-2, 119T-2 protrude at different distances from the second surfaces 99B and 99C, respectively.112B, so that the height of the first and second plurality of protrusions 117S-2, 117T-2, 119S-2, 119T-2 varies. In particular, the height of the first and second plurality of protrusions 117-2, 119-2 in a central region of the first and second coolant channels 104, 116 is greater than the height of the first and second protrusions 117S-2, 117T-2, 119S-2, 119T-2 along the edges of the first and second coolant channels 104, 116, respectively.

[0038] The projections 117-1, 117S-2, 117T-2, 119-1, 119S-2, 119T-2 may form a mechanical stop to limit the compression of the first and second curved sections 102, 114, thus ensuring space for maintaining a desired coolant flow rate. The arrangement of the projections 117, 119 may be configured to compensate for uneven compression of the intermediate layer. For example, the projections 117, 119 extend Fig. 9, the projections 117T-2, 119T-2 are arranged in a central region at a greater distance from the second surfaces 99B, 112B than along the upper and lower edges of the second surfaces 99B, 112B. This configuration of the first and second plurality of projections 117S-2, 117T-2, 119S-2, 119T-2 in Fig. 9 allows for less deflection of the first and second curved portions 102, 114 prior to engagement with projections on adjacent cooling plate assemblies 93, 95.

[0039] As in Fig. 10, the first planar portions 99 of the first coolant plate assembly 93 can be formed by using a male roller 150 configured to roll in a direction R1 and a corresponding female roller 152 configured to roll in a direction R2 to form the protrusions 117. However, the rollers 150, 152 can be used to form the first planar portion 112 for the second coolant plate assembly 95 in the same manner as described for the first coolant plate assembly 93. In particular, the material is fed to the rollers 150, 152 in the direction P so that the male portions 156 of the roller 150 can extrude the material into the corresponding female portions 158 of the roller 152 to form the protrusions 117.

[0040] As in Fig. 11, the first planar portion 99 may include a thermal paste 160 disposed on the first surface 99A. The thermal paste increases the heat transfer between the first coolant plate assembly 93 and the first plurality of energy storage cells 54 by filling the voids in the first surface 99A to improve heat transfer. The first planar surface 99A of the second coolant plate assembly 95 may be attached to the second plurality of energy storage cells 55 in a similar manner. The thermal paste may also be used instead of the adhesives 103, 105 ( Fig. 4) or in addition to the adhesives 103, 105 for securing the first and second coolant plate assemblies 93, 95 to the first and second plurality of energy storage cells 54, 55, respectively.

[0041] The term "a" or "an" does not imply a quantity limitation, but denotes the presence of at least one of the mentioned elements. The term "or" means "and / or" unless the context clearly indicates otherwise. References to "an aspect" throughout this description mean that a particular element (e.g., a feature, structure, step, or property) described in connection with the aspect is included in at least one of the aspects described herein and may or may not be present in other aspects. Furthermore, the described elements in the different aspects may be combined in any suitable way.

[0042] Although various embodiments have been described, the description is intended to be exemplary rather than restrictive. It will be apparent to those skilled in the art that many other embodiments and implementations are possible that fall within the scope of the embodiments. Any feature of one embodiment may be used in combination with, or in place of, another feature or element in another embodiment, unless expressly limited. Accordingly, the embodiments are not to be limited except as with the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

Claims

[1] Battery pack comprising: a first head part with a first line; a second head section with a second line; an energy storage system having a plurality of energy storage cells arranged between the first header and the second header; and a coolant plate assembly disposed between the first header and the second header and adjacent the plurality of energy storage cells, the coolant plate assembly comprising a coolant channel having a first end fluidly connected to the first conduit, a second end fluidly connected to the second conduit, and an intermediate portion defining a flow path, the coolant plate assembly comprising a first planar portion having a first surface facing the plurality of energy storage cells and a second surface having a first plurality of protrusions extending into the coolant channel. [2] The battery pack of claim 1, wherein the first plurality of protrusions comprise different heights relative to the second surface of the first planar portion. [3] The battery pack of claim 1, wherein the first plurality of protrusions are arranged in rows, the first plurality of protrusions in adjacent rows being offset relative to each other in a direction perpendicular to a direction of coolant flow through the coolant channel. [4] Battery pack according to claim 1, comprising: a further plurality of energy storage cells disposed between the first header and the second header and spaced from the plurality of energy storage cells; and a further coolant plate assembly disposed between the first header and the second header and adjacent to each of the further plurality of energy storage cells, the further coolant plate assembly comprising a further coolant channel having a first end portion fluidly connected to the first conduit, a second end portion fluidly connected to the second conduit, and an intermediate portion defining a further flow path, the further coolant plate assembly comprising a second planar portion having a first surface facing the further plurality of energy storage cells and a second surface having a second plurality of projections extending into the further coolant channel. [5] The battery pack of claim 4, wherein the second plurality of protrusions comprise different heights relative to the second surface. [6] The battery pack of claim 4, wherein the second plurality of protrusions are arranged in rows, the second plurality of protrusions in adjacent rows being offset relative to each other in a direction perpendicular to the coolant flow through the other coolant channel. [7] The battery pack of claim 4, wherein the first surface on the first planar portion of the coolant plate assembly is coated with a thermal compound that directly contacts the plurality of energy storage cells, and the first surface on the second planar portion of the other coolant plate is coated with a different thermal compound that directly contacts the other plurality of energy storage cells. [8] The battery pack of claim 4, wherein the coolant plate assembly includes a first curved portion having a first inner surface facing the coolant channel and a first outer surface, and the further coolant plate assembly includes a second curved portion having a second inner surface facing the other coolant channel and a second outer surface. [9] The battery pack of claim 8, wherein the first outer surface of the coolant plate assembly is adjacent to the second outer surface of the other coolant plate assembly at a cooling plate interface. [10] The battery pack of claim 9, comprising a first air gap disposed on a first side of the cold plate interface and a second air gap disposed on a second side of the cold plate interface.

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