Battery pack including potting material and method of making same

Abstract

Battery packs including potting material and methods of making the same are provided. A battery pack includes a first potting material formed between a housing portion and internal components including a battery cell, where the first potting material at least partially forms a network of channels configured to vent gas from the battery cell to an environment during a thermal runaway event.

Description

Technical Field

[0001] The technical field generally involves batteries and their manufacturing methods. Background Technology

[0002] Encapsulation is a process of filling a battery with a solid or gel-like compound to protect the internal battery components from moisture, shock, vibration and other environmental factors, thereby improving reliability and lifespan.

[0003] It is desirable to provide a battery pack having a potting material having a surface with features beneficial to battery operation. Furthermore, other desirable features and characteristics of patentable variations will become apparent from the following detailed description and appended claims, taken in conjunction with the accompanying drawings and the foregoing introduction. Summary of the Invention

[0004] Multiple variations may include a product comprising: a battery pack including a first housing portion and a first potting material therein, wherein the first potting material at least partially forms a channel network configured to vent gases during a thermal runaway event.

[0005] Multiple variations may include a product in which the channel network comprises multiple spaced-apart ribs and multiple spaced-apart channels, wherein one of the multiple spaced-apart channels separates adjacent spaced-apart ribs.

[0006] Multiple variations may include a product that further includes a battery cell bonding panel having a plurality of through holes formed therein, wherein the battery cell bonding panel is adhered to the top surface of each of a plurality of spaced-apart ribs.

[0007] Multiple variations may include a product that further includes a plurality of battery cells, each of the plurality of battery cells including a battery cell vent that is configured and arranged to rupture during a thermal runaway event, thereby creating an opening in the battery cell bonding panel and communicating with at least one of a plurality of spaced-apart channels.

[0008] Multiple variations may include a product in which the first potting material includes at least one of silicone, epoxy resin or polyurethane.

[0009] Multiple variations may include a product in which a first potting material includes a leak detection channel formed therein.

[0010] Multiple variations may include a product in which a first potting material includes a manifold formed therein, wherein the manifold communicates with a plurality of spaced channels.

[0011] Multiple variations may include a product in which a first potting material has an interface channel formed therein, wherein the interface channel communicates with a manifold.

[0012] Multiple variations may include a product further comprising: a battery cell bonding panel having a plurality of through-holes formed therein, wherein the battery cell bonding panel is adhered to the top surface of each of a plurality of spaced-apart ribs; a plurality of battery cells, each of the plurality of battery cells including a battery cell vent configured and arranged to rupture during a thermal runaway event, thereby creating an opening in the battery cell bonding panel and communicating with at least one of a plurality of spaced-apart channels; and a vent box; wherein the channel network includes a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the plurality of spaced-apart channels separates adjacent spaced-apart ribs; wherein a first potting material includes at least one of silicone, epoxy, or polyurethane; wherein the first potting material includes a leak detection channel formed therein; wherein the first potting material includes a manifold formed therein, wherein the manifold communicates with the plurality of spaced-apart channels; wherein the first potting material includes an interface channel formed therein, wherein the interface channel communicates with the manifold; wherein the interface channel communicates with the vent box.

[0013] Multiple variations may include a method of: providing a first housing portion for a battery pack; providing a tool having a plurality of spaced-apart protrusions and a plurality of spaced-apart valleys, wherein one of the plurality of spaced-apart valleys separates adjacent spaced-apart protrusions; inserting at least a portion of the tool having the plurality of spaced-apart protrusions into a potting resin, or inserting at least a portion of the tool having the plurality of spaced-apart protrusions into the first housing portion for the battery pack, and thereafter dispensing potting resin into the first housing portion for the battery pack such that the potting resin flows into the plurality of spaced-apart valleys; curing the potting resin to provide a first potting material; removing the tool; and wherein the first potting material at least partially forms a channel network to expel gas from the battery cell during a thermal runaway event.

[0014] Multiple variations may include a method in which the channel network comprises a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the plurality of spaced-apart channels separates adjacent spaced-apart ribs.

[0015] Multiple variations may include a method in which the tool includes a built-in seal to contain potting resin in an area beneath the tool.

[0016] Multiple variations may include a method that further includes adhering a battery cell bonding panel to the top surface of each of a plurality of spaced-apart ribs, wherein the battery cell bonding panel has a plurality of through holes formed therein.

[0017] Multiple variations may include a method of placing multiple battery cells on a battery cell bonding panel, wherein each of the multiple battery cells includes a battery cell vent aligned with one of a plurality of through holes and a channel of a plurality of spaced-apart channels.

[0018] Multiple variations may include a method that further includes using tools to form a leak inspection channel across the periphery of the first housing portion to enable pressure-based leak inspection.

[0019] Multiple variations may include a method in which curing the potting resin includes heating the potting resin to a temperature of about 40 degrees Celsius to about 70 degrees Celsius.

[0020] Multiple variations may include a method in which curing the potting resin is accomplished using a heating element in the tool.

[0021] Multiple variations may include a method that further includes venting gas through multiple pin holes in the tool during the curing of the potting resin.

[0022] Multiple variations may include a method in which a channel network includes a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the spaced-apart channels separates adjacent spaced-apart ribs; wherein the method further includes adhering a battery cell bonding panel to the top surface of each of the plurality of spaced-apart ribs, wherein the battery cell bonding panel has a plurality of through holes formed therein; using a tool to form a channel manifold and an interface channel, wherein the channel manifold communicates with the plurality of spaced-apart channels and the interface channel, wherein the interface channel communicates with a vent box in a first housing portion for a battery pack; using a tool to form a leak inspection channel across the periphery of the first housing portion to enable pressure-based leak inspection; and placing a plurality of battery cells on the battery cell bonding panel, wherein each of the plurality of battery cells includes a battery cell vent aligned with one of the through holes and a channel of the plurality of spaced-apart channels; wherein the tool includes a built-in seal to accommodate potting resin in a region below the tool.

[0023] Multiple variations may include a product comprising: a vehicle including a battery pack including a first housing portion and a first potting material therein, wherein the first potting material at least partially forms a channel network for venting gases during a thermal runaway event; wherein the channel network includes a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the plurality of spaced-apart channels separates adjacent spaced-apart ribs; a battery cell bonding panel having a plurality of through-holes formed therein, wherein the battery cell bonding panel is adhered to the top surface of each of the plurality of spaced-apart ribs; and a plurality of battery cells. Each of the battery cells includes a battery cell vent that communicates with one of a plurality of through holes in a battery cell bonding panel and with a portion of a plurality of spaced-apart channels; and a vent box; wherein a first potting material includes at least one of silicone, epoxy resin, or polyurethane; wherein the first potting material includes a leak detection channel formed therein; wherein the first potting material includes a manifold formed therein, wherein the manifold communicates with a plurality of spaced-apart channels; wherein the first potting material includes an interface channel formed therein, wherein the interface channel communicates with the manifold; and wherein the interface channel communicates with the vent box. Attached Figure Description

[0024] The illustrative variations will be described below with reference to the following figures, wherein similar numbers denote similar elements, and wherein:

[0025] Figure 1 It is a perspective view of a portion of a battery pack according to several variations, the battery pack including a potting material having a network of channels formed in a first surface of the potting material;

[0026] Figure 2 It is a cross-sectional view of a portion of a battery pack assembly according to several variations, the battery pack assembly including a tool having a plurality of spaced ribs for forming a channel network;

[0027] Figure 3 It is a top view based on several variations of a potting tool, which includes a complex seal that abuts against the edge of an annular component surrounding the battery pack;

[0028] Figure 4 It is a partial top view based on several variations of a potting tool, which includes multiple pinvents.

[0029] Figure 5 This is a partial cross-sectional view showing a tool according to several variations, the tool having a seal that engages the surface of an annular part;

[0030] Figure 6 This is a partial cross-sectional view showing leak inspection channels formed in potting material according to various variations;

[0031] Figure 7 It is a partial top view of several variations, including the battery cell bonding panel;

[0032] Figure 8 It is a partial cross-sectional view based on multiple variations of a battery pack, which includes battery cells, each battery cell having a battery cell vent aligned with a channel in a channel network formed in a potting material;

[0033] Figure 9 The diagram is based on several variants of the vehicle, which includes a battery pack operatively connected to an electric propulsion motor.

[0034] Figure 10 It is a partial perspective view of a portion of a battery pack according to several variations, the battery pack including a potting material having a network of channels formed in a first surface of the potting material;

[0035] Figure 11 It is an enlarged partial perspective view of a portion of a battery pack according to several variations, the battery pack including a potting material having a network of channels formed in a first surface of the potting material;

[0036] Figure 12 It is a partial top view of a potting tool with several variations, including cylindrical protrusions, each for engaging with a dam in a vent box;

[0037] Figure 13 It is a partial top view of a battery pack based on several variations, which includes a vent box with two baffles;

[0038] Figure 14 This is a top view of a portion of a battery pack according to several variations, the battery pack including a potting material having a network of channels and leak detection channels formed in a first surface of the potting material; and

[0039] Figure 15 It is a top view of several variations, including the battery cell bonding panel. Detailed Implementation

[0040] The following detailed description is illustrative in nature only and is not intended to limit application or use. Furthermore, it is not intended to be bound by any express or implied theory presented in the foregoing introduction, description of the figures, summary of the invention, or the following detailed description.

[0041] like Figure 1 and Figure 10As shown, the battery pack 30 may include a first housing portion 32. The first housing portion 32 may be a single part or multiple parts, such as, but not limited to, an intermediate part 34 having a first end 36 and an opposing second end 38. The first housing portion 32 may include a first end cap 40 attached to the first end 36 of the intermediate part 34 and a second end cap 42 attached to the second end 38 of the intermediate part 34. At least one of the first end cap 40 and the second end cap 42 may include a battery pack vent valve 44. A first potting material 46 may be formed or contained in the first housing portion 32. The first potting material 46 may be any of a variety of polymeric materials, including but not limited to silicone, epoxy resin, and polyurethane. The first surface 48 of the first potting material 46 may include a channel network 50, which may include a plurality of spaced-apart ribs 52 and a plurality of spaced-apart channels 58. Each channel 58 is at least partially formed by a pair of adjacent protrusions (in the spaced-apart protrusions 72) of a plurality of spaced-apart protrusions 72. Figure 2 The first potting material 46 is most clearly defined, for example, by a first rib 54 and a spaced-apart second rib 56, with a channel 58 between them. Each channel 58 defined in the first surface 48 of the first potting material 46 can communicate with a manifold 60. An interface channel 62 can communicate with the manifold 60 and a vent box 64 connected to the battery pack vent valve 44. A leak detection channel 63 can be formed in the first potting material 46 and connected to the battery pack vent valve 44, allowing gas to flow through the leak detection channel 63 and each of the plurality of spaced-apart channels 58. Figure 14 As shown, the leak inspection channel 63 can extend around the entire periphery of the first potting material 46.

[0042] refer to Figures 1-4 The first potting material 46 may be formed using a tool 66 having a top surface 68, an opposing bottom surface 70, and a plurality of spaced-apart protrusions 72 extending from the bottom surface. Adjacent spaced-apart protrusions 72 define valleys 74 therebetween. The tool 66 may include a peripheral seal 76 on the bottom surface 70. As will be described below, the peripheral seal 76 may engage an annular member 80. At least a portion of the tool 66 may be inserted into the first housing portion 32. Potting resin may be dispensed into the first housing portion 32 such that the potting resin flows into each valley 74 to form Figure 1 The diagram shows a plurality of spaced-apart ribs 52. Alternatively, potting resin may be dispensed into the first housing portion 32, and at least a portion of the tool 66 having a plurality of spaced-apart protrusions 72 may thereafter be inserted into the potting resin in the first housing portion 32. Figure 3 As shown, the manifold forming protrusion 82 and the interface channel forming protrusion 84 can extend from the bottom surface 70 of the tool 66. Figure 4 As shown, tool 66 may include multiple pins 86 (also in...) Figure 12(as shown in the diagram) to contain gases expelled through tool 66 as the resin material is dispensed into the first housing portion 32. Tool 66 can be heated, for example, to a maximum of about 100 degrees Celsius, or to a temperature in the range of about 40 degrees Celsius to about 70 degrees Celsius, to cure the potting resin.

[0043] refer to Figures 5-6 The battery pack 30 may include an annular member 80. The tool 66 may have a peripheral seal 76 with angled faces 78 to engage the annular member 80. A leak detection channel 63 formed in the first potting material 46 and the peripheral seal 76 of the tool engage the annular member 80.

[0044] Figures 7-8 and Figure 15 A battery cell bonding panel 90 is shown, which may have a plurality of through holes 92 formed therein. (Example) Figure 7 As shown, the battery cell bonding panel 90 can be a mica sheet. The battery pack 30 can have a second housing portion 96. Figure 8 As shown, the battery pack 30 may include a plurality of battery cells 98, each battery cell having electrical terminals 100 for connection to a busbar 102 or for delivering electrical energy. Each of the plurality of battery cells 98 may have a battery cell vent 104 configured and arranged to rupture during a thermal runaway event, thereby creating an opening in a battery cell bonding panel and communicating with at least one of a plurality of spaced-apart channels 58. The battery cell bonding panel 90 may be adhered to the top surface 94 of each of a plurality of spaced-apart ribs 52. One of the through-holes 92 communicates with at least one of the plurality of spaced-apart channels 58 formed in a first potting material 46. A second potting material 106 may be formed around the plurality of battery cells 98. The second potting material 106 may be the same as or different from the first potting material 46. Tool 66 can mate with the obstruction 93 around the battery pack vent valve 44 to create a continuous path from the battery cell vent 104 to the battery pack vent valve 44, unobstructed by potting compound. Figure 15 As shown, the battery pack 30 includes a battery cell bonding panel 90 with through holes 92 of different sizes and patterns.

[0045] Figure 9 A vehicle 108 according to several variants is shown, which includes a battery pack 30, as described herein, which is operatively connected to an electric propulsion motor 110.

[0046] refer to Figures 12-13Tool 66 may include a blocking engagement feature 85 to engage a blocking member 93 on the vent box 64, thereby preventing potting resin from flowing into the blocking member. The blocking engagement feature 85 may be a protrusion for engaging the top of the blocking member 93 or a recess for receiving the blocking member 93 therein.

[0047] While at least one variation has been presented in the foregoing detailed description, it should be understood that numerous variations exist. It should also be understood that one or more variations are merely examples and are not intended to limit the scope, applicability, or configuration of this disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing one or more illustrative variations. It should be understood that various changes can be made to the function and arrangement of the elements without departing from the scope of this disclosure as set forth in the appended claims and their legal equivalents.

Claims

1. A product comprising: A battery pack, the battery pack including a first housing portion and a first potting material therein, wherein the first potting material at least partially forms a channel network configured to vent gas during a thermal runaway event.

2. The product of claim 1, wherein the channel network comprises a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the plurality of spaced-apart channels separates adjacent spaced-apart ribs.

3. The product of claim 2 further includes a battery cell bonding panel having a plurality of through holes formed therein, wherein the battery cell bonding panel is adhered to the top surface of each of the plurality of spaced-apart ribs.

4. The product of claim 3 further comprises a plurality of battery cells, each of the plurality of battery cells including a battery cell vent, the battery cell vent being configured and arranged to rupture during a thermal runaway event, thereby creating an opening in the battery cell bonding panel and communicating with at least one of the plurality of spaced-apart channels.

5. The product according to claim 1, wherein the first potting material comprises at least one of silicone, epoxy resin or polyurethane.

6. The product of claim 1, wherein the first potting material includes a leak detection channel formed therein.

7. The product of claim 2, wherein the first potting material includes a manifold formed therein, wherein the manifold is in communication with the plurality of spaced-apart channels.

8. The product of claim 7, wherein the first potting material has an interface channel formed therein, wherein the interface channel is in communication with the manifold.

9. The product according to claim 8, further comprising: A battery cell bonding panel having a plurality of through holes formed therein, wherein the battery cell bonding panel is adhered to the top surface of each of the plurality of spaced-apart ribs. A plurality of battery cells, each of the plurality of battery cells including a battery cell vent, the battery cell vent communicating with one of the plurality of through holes in the battery cell mating panel and with a channel in the plurality of spaced channels; and Ventilation box; The channel network includes a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the plurality of spaced-apart channels separates adjacent spaced-apart ribs. The first potting material includes at least one of silicone, epoxy resin or polyurethane; The first potting material includes a leak inspection channel formed therein; The first potting material includes a manifold formed therein, wherein the manifold is in communication with the plurality of spaced-apart channels; The first potting material includes an interface channel formed therein, wherein the interface channel communicates with the manifold; and The interface channel is connected to the ventilation box.

10. A product comprising: A vehicle, the vehicle including a battery pack, the battery pack including a first housing portion and a first potting material therein, wherein the first potting material at least partially forms a channel network to vent gases during a thermal runaway event; The channel network includes a plurality of spaced-apart ribs and a plurality of spaced-apart channels, wherein one of the plurality of spaced-apart channels separates adjacent spaced-apart ribs. A battery cell bonding panel having a plurality of through holes formed therein, wherein the battery cell bonding panel is adhered to the top surface of each of the plurality of spaced-apart ribs. A plurality of battery cells, each of the plurality of battery cells including a battery cell vent, the battery cell vent being configured and arranged to rupture during a thermal runaway event, thereby creating an opening in the battery cell bonding panel and communicating with at least one of the plurality of spaced-apart channels; and Ventilation box; The first potting material includes at least one of silicone, epoxy resin or polyurethane; The first potting material includes a leak inspection channel formed therein; The first potting material includes a manifold formed therein, wherein the manifold is in communication with the plurality of spaced-apart channels; The first potting material includes an interface channel formed therein, wherein the interface channel communicates with the manifold; and The interface channel is connected to the ventilation box.

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