Battery cell design to facilitate increased heat transfer and thermal performance

Abstract

The present disclosure provides a battery cell design that helps increase heat transfer and thermal performance. A battery cell for use within a traction battery pack is described. The exemplary battery cell includes a design that helps increase heat transfer and thermal performance. For example, an exemplary prismatic battery cell may include an electrode assembly having a plurality of electrode stack layers, and each electrode stack layer of the plurality of electrode stack layers includes a major side surface positioned orthogonal to a major face of a prismatic outer housing of the cell. An example cylindrical battery cell may include a first plurality of mounts projecting outwardly from a base of a cylindrical outer housing of the cell, and a second plurality of mounts projecting outwardly from a cap of the cell. When the cylindrical battery cell and an additional cylindrical battery cell are stacked together, the holders cooperate to establish a cooling channel.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to battery cells, and more particularly, to battery cell designs that facilitate increased heat transfer and thermal performance. BACKGROUND

[0002] High-voltage traction battery packs generally power electric machines and other electrical loads of electrically powered vehicles. Traction battery packs include a plurality of battery cells. Some traction battery packs utilize pouch battery cells. SUMMARY

[0003] A prismatic battery cell according to example aspects of the present disclosure includes, among other things, a prismatic outer housing including a first major face and a second major face, and an electrode assembly disposed inside the prismatic outer housing. The electrode assembly includes a plurality of electrode stack layers, and each electrode stack layer of the plurality of electrode stack layers includes a major side surface positioned orthogonal to the first major face and the second major face of the prismatic outer housing.

[0004] In another non-limiting embodiment of the foregoing prismatic battery cell, the plurality of electrode stack layers are vertically stacked on top of one another such that each of the major side surfaces extends parallel to a minor face located at a top or a bottom of the prismatic outer housing.

[0005] In another non-limiting embodiment of any of the foregoing prismatic battery cells, the major side surfaces of the plurality of electrode stack layers extend longitudinally in a width direction of the prismatic outer housing.

[0006] In another non-limiting embodiment of any of the foregoing prismatic battery cells, a height of the prismatic outer housing is greater than the width to establish a high-layer configuration of the prismatic battery cell.

[0007] In another non-limiting embodiment of any of the foregoing prismatic battery cells, the plurality of electrode stack layers are horizontally and side-by-side stacked with one another such that the major side surfaces extend parallel to a minor face located at each opposing end of the prismatic outer housing.

[0008] In another non-limiting embodiment of any of the foregoing prismatic battery cells, the major side surfaces of the plurality of electrode stack layers extend longitudinally in a height direction of the prismatic outer housing.

[0009] In another non-limiting embodiment of any of the foregoing prismatic battery cells, a height of the prismatic outer housing is greater than the width to establish a high-layer configuration of the prismatic battery cell.

[0010] In another non-limiting embodiment of any of the foregoing prismatic battery cells, a plurality of standoffs protrude outwardly from the first major face and the second major face.

[0011] In another non-limiting embodiment of any of the foregoing prismatic battery cells, the plurality of standoffs are fins, ribs, or dimples.

[0012] In another non-limiting embodiment of any of the foregoing prismatic battery cells, the plurality of standoffs extend vertically or horizontally across the first major face and the second major face.

[0013] A cylindrical battery cell according to another exemplary aspect of the present disclosure includes, among other things, a cylindrical housing assembly including a cylindrical outer housing and a lid. A base of the cylindrical outer housing and the lid establish major side surfaces of the cylindrical housing assembly. An electrode assembly is disposed inside the cylindrical outer housing. A first plurality of standoffs protrude outwardly from the base of the cylindrical outer housing, and a second plurality of standoffs protrude outwardly from the lid.

[0014] In another non-limiting embodiment of the foregoing cylindrical battery cell, the electrode assembly includes a jellyroll body having a major side surface that is orthogonal to the major side surfaces of the cylindrical housing assembly.

[0015] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, the jellyroll body includes a cinnamon roll-like geometric configuration.

[0016] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, the first plurality of standoffs are male standoffs, and the second plurality of standoffs are female standoffs.

[0017] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, the male standoffs are configured to engage a set of female standoffs of an adjacent cylindrical battery cell.

[0018] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, a cooling channel extends between the cylindrical battery cell and the adjacent cylindrical battery cell.

[0019] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, the cooling channel establishes a tortuous path between the cylindrical battery cell and the adjacent cylindrical battery cell.

[0020] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, at least one of the first plurality of standoffs or the second plurality of standoffs is configured to collapse or wrinkle under axial impact loading.

[0021] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, the side wall of the cylindrical outer housing establishes a minor side surface of the cylindrical housing assembly.

[0022] In another non-limiting embodiment of any of the foregoing cylindrical battery cells, the cylindrical outer housing and the cover are made of aluminum.

[0023] The foregoing paragraphs, claims, or embodiments, examples, and alternatives of the following description and drawings, including any of their various aspects or corresponding individual features, can be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible.

[0024] Various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 An electrically powered vehicle is schematically illustrated.

[0026] Figure 2 A perspective view of a traction battery pack of an electrically powered vehicle.

[0027] Figure 3 A prismatic battery cell is illustrated.

[0028] Figure 4 Another exemplary prismatic battery cell is illustrated.

[0029] Figure 5 A prismatic battery cell of Figure 3 is schematically illustrated.

[0030] Figure 6 A standoff feature of a prismatic outer housing of a prismatic battery cell is illustrated.

[0031] Figure 7 An alternative standoff feature of a prismatic outer housing of a prismatic battery cell is illustrated.

[0032] Figure 8 An alternative standoff feature of a prismatic outer housing of a prismatic battery cell is illustrated.

[0033] Figure 9 A plurality of prismatic battery cells arranged into a cell stack are illustrated.

[0034] Figure 10 A plurality of prismatic battery cells arranged into a cell stack are illustrated.

[0035] Figure 11This is a perspective view of a cylindrical battery cell.

[0036] Figure 12 yes Figure 11 A side view of a cylindrical battery cell.

[0037] Figure 13 It shows Figure 11 The electrode assembly of a cylindrical battery cell.

[0038] Figure 14 It shows Figure 11 The heat transfer diagram of a cylindrical battery cell.

[0039] Figure 15 and Figure 16 The support features for a cylindrical battery cell are shown.

[0040] Figure 17 This shows multiple cylindrical battery cells arranged in a cell stack.

[0041] Figure 18 Is it through Figure 17 The cross-sectional view of section 18-18. Detailed Implementation

[0042] This disclosure details battery cells used within traction battery packs. Exemplary battery cells include designs that contribute to increased heat transfer and thermal performance. An exemplary prismatic battery cell may include an electrode assembly having multiple electrode stacks, each of the multiple electrode stacks including a main side surface orthogonal to the main face of the prismatic housing of the cell. An exemplary cylindrical battery cell may include a first plurality of supports projecting outward from the base of the cylindrical housing of the cell, and a second plurality of supports projecting outward from the cap of the cell. When the cylindrical battery cell is stacked with additional cylindrical battery cells, the supports cooperate to establish cooling channels. These and other features are discussed in more detail in the following paragraphs of this detailed description.

[0043] Figure 1 An electrified vehicle 10 is schematically illustrated. The electrified vehicle 10 may include any type of electrified powertrain. In this embodiment, the electrified vehicle 10 is a battery electric vehicle (BEV). However, the concepts described herein are not limited to BEVs and can be extended to other electrified vehicles, including but not limited to hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, etc. Therefore, although not specifically shown in the exemplary embodiments, the powertrain of the electrified vehicle 10 may be equipped with an internal combustion engine, which may be used alone or in combination with other power sources to propel the electrified vehicle 10.

[0044] In the illustrated embodiment, the electrified vehicle 10 is depicted as an automobile. However, the electrified vehicle 10 may alternatively be a sports utility vehicle (SUV), van, pickup truck, or any other vehicle configuration. Although specific component relationships are shown in the accompanying drawings of this disclosure, the illustrations are not intended to limit the scope of this disclosure. The placement and orientation of the various components of the electrified vehicle 10 are schematically shown and may vary within the scope of this disclosure. Furthermore, the various drawings accompanying this disclosure are not necessarily drawn to scale, and some features may be enlarged or minimized to emphasize certain details of particular components or systems.

[0045] In the illustrated embodiment, the electrified vehicle 10 is a purely electric vehicle propelled solely by electricity (such as by one or more motors 12) without the assistance of an internal combustion engine. The motor 12 may operate as an electric motor, a generator, or both. The motor 12 receives electricity and can convert that electricity into torque for driving one or more wheels 14 of the electrified vehicle 10.

[0046] Voltage bus 16 can electrically connect motor 12 to traction battery pack 18. Traction battery pack 18 is an exemplary electric vehicle battery. Traction battery pack 18 can be a high-voltage traction battery pack assembly including multiple battery cells capable of outputting power to supply motor 12 and / or other electrical loads of electric vehicle 10. Other types of energy storage devices and / or output devices may alternatively or additionally be used to supply power to electric vehicle 10.

[0047] The traction battery pack 18 can be fixed to the bottom 20 of the electric vehicle 10. However, within the scope of this disclosure, the traction battery pack 18 can be located elsewhere on the electric vehicle 10.

[0048] Figure 2 Additional details associated with the traction battery pack 18 of the electrified vehicle 10 are schematically shown. The traction battery pack 18 may include one or more battery arrays 22 (e.g., groups of battery modules or rechargeable battery cells 24) capable of outputting power to supply the motor 12 and / or other electrical loads of the electrified vehicle 10. Other types of energy storage devices and / or output devices may alternatively or additionally be used to supply power to the electrified vehicle 10.

[0049] Battery cells 24 may be stacked together along a stacking axis to form a group of battery cells 24, sometimes referred to as a "cell stack". When the traction battery pack 18 is mounted on the electrified vehicle 10, the battery array 22 may extend in the lateral direction of the vehicle. However, other configurations are also possible. The total number of battery arrays 22 and battery cells 24 provided within the traction battery pack 18 is not intended to limit this disclosure.

[0050] In this embodiment, the battery cell 24 of each battery array 22 is a lithium-ion cell. However, battery cells with other chemical compositions (e.g., nickel metal hydride, lead acid, sodium ion, lithium sulfur, lithium silicon, etc.) may also be used within the scope of this disclosure.

[0051] Battery array 22 and various other internal battery components (e.g., bus electrical hub, battery electrical control module, wiring, connectors, etc.) can be housed within housing assembly 28. Housing assembly 28 may include housing cover 30 and housing tray 32. Housing cover 30 may be secured (e.g., bolted, welded, adhered, etc.) to housing tray 32 to provide an internal area 26 for housing battery array 22. The size, shape, and overall configuration of housing assembly 28 are not intended to limit this disclosure.

[0052] Figure 3 It shows that it can be done in, for example Figures 1-2 The prism-shaped battery cell 24-1 is utilized within the battery array 22 of the traction battery pack 18. The prism-shaped battery cell 24-1 includes a prism-shaped housing 34 and an electrode assembly 36 encapsulated within the prism-shaped housing 34.

[0053] The prismatic housing 34 can be a relatively rigid structure constructed from a metallic material such as aluminum. The prismatic housing 34 can be rectangular and includes a height H, a width W, and a thickness T. In an embodiment, the height H is greater than the width W or the thickness T. The prismatic battery cell 24-1 is therefore considered to have a "high-level" configuration.

[0054] The prismatic outer shell 34 includes a main surface 38 and a secondary surface 40. The main surface 38 exhibits a larger surface area than the secondary surface 40 of the prismatic outer shell 34.

[0055] The electrode assembly 36 may include multiple electrode stack layers 42. Each electrode stack layer 42 includes a cathode, an anode, and one or more separators (not shown for simplicity and clarity).

[0056] Electrode stack layers 42 can be stacked together and arranged inside the prismatic housing 34. Each electrode stack layer 42 can be arranged such that the main side surface 44 of each electrode stack layer 42 is orthogonal (i.e., perpendicular) to the main surface 38 of the prismatic housing 34.

[0057] In one embodiment, the electrode stack layers 42 are vertically stacked on top of each other, such that the main side surface 44 of the electrode stack layers 42 extends parallel to the secondary surface 40 located at the top and bottom of the prismatic housing 34 (see...). Figure 3 In this embodiment, the main side surface 44 extends longitudinally in the direction of the width W of the prismatic outer shell 34.

[0058] In another embodiment, the electrode stack layers 42 are stacked horizontally side by side such that the main side surface 44 of the electrode stack layers 42 extends parallel to the secondary surface 40 located at each opposite end of the prismatic housing 34 (see...). Figure 4 In this embodiment, the main side surface 44 extends longitudinally in the direction of the height H of the prismatic outer shell 34.

[0059] Arranging the main side surfaces 44 of the electrode stack 42 orthogonal to the main face 38 of the prismatic housing 34 optimizes the main face 38 of the prismatic housing 34 and minimizes the average in-plane transfer distance from each electrode stack 42 to the main face 38. Therefore, the prismatic battery cell 24-1 can provide increased heat transfer into / out of the main face 38 of the prismatic housing 34 (e.g., ...). Figure 5 (Arrow 46 is shown schematically in the diagram), and thus contributes to increased cell cooling and thermal management performance.

[0060] Now for reference Figure 6 , Figure 7 and Figure 8 The prismatic housing 34 of the prismatic battery cell 24-1 may include a plurality of supports 48 configured to physically separate the prismatic battery cell 24-1 from adjacent battery cells within the battery array. The supports 48 may be provided on the main surface 38 of the prismatic housing 34 and may be arranged to extend horizontally (see...). Figure 6 ) or extend vertically (see Figure 7 Support 48 can be configured as a fin or a rib (see...). Figure 6 and Figure 7 ) or pit (see Figure 8 ).

[0061] Now for reference Figure 9 and Figure 10 Prismatic battery cells 24-1 can be stacked together with other prismatic battery cells 24-1 to construct a battery cell stack 50. Supports 48 physically separate the prismatic battery cells 24-1 from each other and establish cooling channels 52 extending therebetween. Cooling fluid F (e.g., air) can be delivered through the cooling channels 52 and thus can directly contact the main surfaces 38 of the prismatic battery cells 24-1, thereby optimizing thermal management performance.

[0062] In this embodiment, the supports 48 of adjacent prismatic battery cells 24-1 are aligned and adjacent to each other to establish a cooling channel 52 (see...). Figure 9 In another embodiment, the supports 48 of adjacent prismatic battery cells 24-1 are staggered to establish cooling channels 52 and allow cooling fluid F to travel along a tortuous path P between the cells (see...). Figure 10 ).

[0063] Figures 11-14 It shows that it can be done in, for example Figures 1-2 Cylindrical battery cells 24-2 are utilized within the battery array 22 of the traction battery pack 18. The cylindrical battery cell 24-2 includes a cylindrical housing assembly 60 and an electrode assembly 62 disposed within the cylindrical housing assembly 60 (see...). Figure 13 ).

[0064] The cylindrical housing assembly 60 may include a cylindrical outer shell 64 and a cover 66. The cover 66 may be fixed to the cylindrical outer shell 64 to house the electrode assembly 62 therein. The cylindrical outer shell 64 and the cover 66 may be relatively rigid structures constructed from a metallic material such as aluminum. Figure 13 The cover 66 has been removed to better show the electrode assembly 62.

[0065] The cylindrical housing assembly 60 includes a diameter dimension D and an axial dimension A (see...). Figure 12 In one embodiment, the diameter dimension D is larger than the axial dimension A. In another embodiment, the diameter dimension D is approximately two, three, or four times the axial dimension A. However, the aspect ratio established by the diameter dimension D is greater than other ratios that the axial dimension A can provide. The cylindrical battery cell 24-2 is considered to have a button-like configuration.

[0066] Due to the aspect ratio established by making the diameter D larger than the axial dimension A, the cap 66 and base 68 of the cylindrical outer shell 64 form the primary side surface of the cylindrical shell assembly 60, and the sidewall 70 of the cylindrical outer shell 64 forms the secondary side surface of the cylindrical shell assembly 60. The primary side surface exhibits a larger surface area than the secondary side surface of the cylindrical shell assembly 60.

[0067] Electrode assembly 62 may sometimes be referred to as a "jelly roll" or active material, and includes a cathode, an anode, and one or more septa (not shown for simplicity and clarity). Electrode assembly 62 may include a wound body 72 wound around a winding axis 74. The wound body 72 may be arranged within a cylindrical housing 64 such that the main side surface 76 of electrode assembly 62 is orthogonal (i.e., perpendicular) to the main side surface provided by cap 66 and base 68. Thus, electrode assembly 62 is considered to have a cinnamon roll geometry.

[0068] Arranging the main side surface 76 of the electrode assembly 62 orthogonal to the main side surface of the cylindrical housing assembly 60 optimizes the main surface of the cylindrical battery cell 24-2 and minimizes the average in-plane transfer distance from the electrode assembly 62 to the main side surface provided by the cap 66 and the base 68. Therefore, the cylindrical battery cell 24-2 can provide increased heat transfer into / out of the main side surface of the cylindrical battery cell 24-2 (e.g., ...). Figure 14(Arrow 78 is shown schematically in the image), and thus contributes to increased cell cooling and thermal management performance.

[0069] The cylindrical battery cell 24-2 can also employ a "tackless" design, in which the electrode assembly 62 is electrically connected to the cover 66 and / or the base 68 without the use of current collector contacts. This design allows the cell to be configured for easier cooling on the large axial end surface of the cylindrical housing assembly 60.

[0070] Now for reference Figure 15 , Figure 16 , Figure 17 and Figure 18 The cylindrical housing assembly 60 of the cylindrical battery cell 24-2 may include a plurality of supports configured to physically separate the cylindrical battery cell 24-2 from adjacent battery cells within the battery array. A first plurality of supports 80-1 may protrude outward from the base 68 of the cylindrical housing 64, and a second plurality of supports 80-2 may protrude outward from the cover 66.

[0071] Cylindrical battery cell 24-2 can be stacked together with other cylindrical battery cells 24-2 to construct cell stack 82 (see...). Figure 17 Supports 80-1 and 80-2 physically separate the cylindrical battery cells 24-2 from each other and establish a cooling channel 84 extending therebetween. Cooling fluid F (e.g., air) can be delivered through the cooling channel 84 and thus can directly contact the main side surfaces of the cylindrical battery cells 24-2 (e.g., caps 66 and bases 68), thereby optimizing thermal management performance.

[0072] The first plurality of supports 80-1 can be configured as convex supports, and the second plurality of supports 80-2 can be configured as concave supports. The first plurality of supports 80-1 of a cylindrical battery cell 24-2 in the cell stack 82 can engage with the second plurality of supports 80-2 of an adjacent cylindrical battery cell 24-2 in the cell stack 82 (e.g., interlocking, see...). Figure 18 This allows the cells to be spaced apart and creates cooling channels 84. The cooling fluid F can travel along the tortuous path P between the cells above and around the joint supports 80-1, 80-2 to provide an increased cooling effect.

[0073] In an embodiment, the first plurality of supports 80-1 and / or the second plurality of supports 80-2 may be designed to collapse, wrinkle, or otherwise fail under axial impact loads guided across the stacking axis of the cell stack 82. Thus, supports 80-1, 80-2 can absorb impact energy that would otherwise be directed into the cylindrical housing assembly 60 of the cylindrical battery cell 24-2.

[0074] The battery cell design variant described in this paper supports increased heat transfer capabilities and reduces the temperature gradient range and peak temperature within the cell. Therefore, the proposed design extends the battery cell's lifespan compared to conventional battery cell designs.

[0075] While different non-limiting embodiments are shown having specific components or steps, the embodiments disclosed herein are not limited to these particular combinations. Some of the components or features from any of the non-limiting embodiments may be used in combination with features or components from any of the other non-limiting embodiments.

[0076] It should be understood that the same reference numerals identify corresponding or similar elements throughout all the figures. It should be understood that although particular arrangements of components are disclosed and shown in these exemplary embodiments, other arrangements may also benefit from the teachings of this disclosure.

[0077] The foregoing description should be interpreted as illustrative and not restrictive. Those skilled in the art will understand that certain modifications may be made within the scope of this disclosure. For these reasons, the appended claims should be examined to determine the true scope and content of this disclosure.

Claims

1. A prismatic battery cell, comprising: A prismatic outer shell, the prismatic outer shell comprising a first main surface and a second main surface; as well as Electrode assembly, the electrode assembly being arranged inside the prismatic housing, The electrode assembly includes multiple electrode stacks, and each of the multiple electrode stacks includes a main side surface orthogonally positioned to the first main surface and the second main surface.

2. The prismatic battery cell of claim 1, wherein the plurality of electrode stacks are stacked vertically on top of each other such that each of the main side surfaces extends parallel to a secondary face located at the top or bottom of the prismatic housing.

3. The prismatic battery cell of claim 2, wherein the main side surface of the plurality of electrode stacks extends longitudinally in the width direction of the prismatic housing.

4. The prismatic battery cell of claim 3, wherein the height of the prismatic housing is greater than the width to establish a high-level configuration of the prismatic battery cell.

5. The prismatic battery cell of any of the preceding claims, wherein the plurality of electrode stacks are stacked horizontally side by side such that the main side surface extends parallel to the secondary surface located at each opposite end of the prismatic housing.

6. The prismatic battery cell of claim 5, wherein the main side surface of the plurality of electrode stacks extends longitudinally in the height direction of the prismatic housing.

7. The prismatic battery cell of claim 6, wherein the height is greater than the width of the prismatic housing to establish a high-level configuration of the prismatic battery cell.

8. The prismatic battery cell of any of the preceding claims, comprising a plurality of supports projecting outward from the first main surface and the second main surface, and optionally, wherein the plurality of supports are fins, ribs or recesses, and also optionally, wherein the plurality of supports extend vertically or horizontally across the first main surface and the second main surface.

9. A cylindrical battery cell, comprising: A cylindrical housing assembly, comprising a cylindrical outer shell and a cover. The base of the cylindrical outer shell and the cap form the main side surface of the cylindrical shell assembly; An electrode assembly, wherein the electrode assembly is arranged inside the cylindrical housing; A plurality of supports protrude outward from the base of the cylindrical outer shell; as well as The second plurality of supports protrude outward from the cover.

10. The cylindrical battery cell of claim 9, wherein the electrode assembly includes a winding body having a main side surface orthogonal to the main side surface of the cylindrical housing assembly, and optionally, wherein the winding body includes a cinnamon roll geometry.

11. The cylindrical battery cell of claim 9 or 10, wherein the first plurality of supports are convex supports and the second plurality of supports are concave supports, and optionally, wherein the convex supports are configured to engage a set of concave supports adjacent to the cylindrical battery cell.

12. The cylindrical battery cell of claim 11, comprising a cooling channel extending between the cylindrical battery cell and the adjacent cylindrical battery cell, and optionally, wherein the cooling channel establishes a tortuous path between the cylindrical battery cell and the adjacent cylindrical battery cell.

13. The cylindrical battery cell of any one of claims 9 to 12, wherein at least one of the first plurality of supports or the second plurality of supports is configured to collapse or wrinkle under axial impact load.

14. The cylindrical battery cell according to any one of claims 9 to 13, wherein the sidewalls of the cylindrical housing form the secondary side surface of the cylindrical housing assembly.

15. The cylindrical battery cell according to any one of claims 9 to 14, wherein the cylindrical outer casing and the cap are made of aluminum.

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