Method for filling battery pack with expanded foam filling body by ventilating air outside filling region

Abstract

A battery module includes a housing including a sidewall structure, a top shear plate, and a bottom shear plate. A ventilation tray assembly is disposed within the housing and includes a unit tray and a ventilation tray that combine to define a plurality of ventilation channels therebetween. The unit tray includes a base plate having a plurality of ventilation openings in communication with one of the plurality of ventilation channels. The ventilated tray assembly includes a plurality of air vents therethrough, the plurality of air vents being isolated from the plurality of ventilation channels. The plurality of battery cells each have an end with a vent aligned with one of the vent openings in the base plate in the cell tray. Filling foam is dispersed within the housing and between the cells.

Description

Technical Field

[0001] The present disclosure relates to a method for filling a battery pack with an expanded foam filler by venting air outside a filling area. Background Art

[0002] The information provided in this section is for the purpose of generally presenting the background of the present disclosure. To the extent described in this section, the work of the currently named inventors and aspects that may not otherwise be described as prior art at the time of filing are neither expressly nor impliedly considered prior art to the present disclosure.

[0003] Cylindrical unit battery packs typically require a filling material to be encapsulated around the units to provide structural support and protection against thermal runaway propagation. Automotive battery packs have used ventilation systems that allow individual battery cells to be ventilated through a passage system that isolates the passage from the rest of the battery pack. To allow gas to reach the ventilation ports of the pack, the ventilation system must remain open for the gas to pass through during a thermal event. Thus, during the filling process, it is necessary to prevent the filler from entering the ventilation system.

[0004] Although foam fillers are used in a variety of automotive battery packs on the market, voids are a common occurrence. Voids can be created due to underfilling or entrained air. The presence of voids can adversely affect thermal runaway performance by allowing overheated gas to move between cells or in high voltage areas, as well as reduce structural performance due to reduced material and non-uniform distribution. Foam fillers are typically composed of polyurethane, but can also be epoxy, silicone, or other resins. The filler is dispensed as a liquid resin and then expands due to a chemical reaction. After a period of time, the material fully expands and hardens to form a foamed plastic material. During expansion, the foam vents air, which must be removed from the battery pack to avoid voids. However, the air ventilation ports risk allowing the foaming resin to pass through, which can result in blockage of the ventilation area that must remain free of the filler. Summary of the Invention

[0005] In accordance with the principles of the present disclosure, the filler is dispensed around and within modules. As the filler expands into foam, air is pushed towards strategically located vents. The air is pushed from the bottom of the pack into a passthrough and into an open cell foam ventilation band. The air is allowed to leave the pack by traveling through open channels within the open cell foam and between the foam.

[0006] According to one aspect of the present disclosure, a battery module includes a housing that includes a sidewall structure, a top shear plate, and a bottom shear plate. A ventilation tray assembly is disposed within the housing and includes a cell tray and a ventilation tray, and the cell tray and the ventilation tray are combined to define a plurality of ventilation channels therebetween. The cell tray includes a base plate having a plurality of ventilation openings that communicate with one of the plurality of ventilation channels. The ventilation tray assembly includes a plurality of air vents that pass therethrough, and the plurality of air vents are isolated from the plurality of ventilation channels. Each of the plurality of battery cells has an end with a vent that is aligned with one of the ventilation openings in the base plate of the cell tray. Filling foam is dispersed within the housing and between the batteries.

[0007] According to another aspect, the cell tray includes a plurality of parallel ribs extending from the base plate of the cell tray, and the ventilation tray includes a base plate and a plurality of parallel ribs extending from the base plate of the ventilation tray, and the plurality of parallel ribs of the cell tray and the plurality of parallel ribs of the ventilation tray are combined to form the plurality of ventilation channels.

[0008] According to another aspect, each air vent is covered with a semi-permeable medium.

[0009] According to another aspect, the plurality of air vents are defined by a plurality of first through-holes in the cell tray and a plurality of second through-holes in the ventilation tray, and the plurality of second through-holes are aligned with a corresponding one of the plurality of first through-holes in the cell tray.

[0010] According to another aspect, the plurality of second through-holes are covered with a semi-permeable medium.

[0011] According to another aspect, each of the plurality of through-holes in the cell tray includes a protruding portion surrounding the through-hole.

[0012] According to another aspect, each of the plurality of through-holes in the ventilation tray includes a protruding portion surrounding the through-hole.

[0013] According to another aspect, a fitting extends between the plurality of through-holes in the cell tray and the plurality of through-holes in the ventilation tray.

[0014] According to another aspect, the ventilation tray includes a base plate and a plurality of pairs of parallel ribs, and the plurality of pairs of parallel ribs are aligned with a corresponding one of the plurality of parallel ribs of the cell tray to define the plurality of ventilation channels.

[0015] According to another aspect, the plurality of air vents are aligned on opposite sides of a ventilation passage that communicates with an opening that vents to the atmosphere.

[0016] According to another aspect, a method of fabricating a battery module includes: inserting a plurality of battery cells into an upside-down housing having a top shear plate and a sidewall structure. Placing a ventilation tray assembly on top of the batteries, the ventilation tray assembly including a cell tray and a ventilation tray, the cell tray and the ventilation tray being combined to define a plurality of ventilation channels therebetween, the cell tray including a base plate having a plurality of ventilation openings in communication with one of the plurality of ventilation channels, the ventilation tray assembly including a plurality of air vents therethrough, the plurality of air vents being isolated from the plurality of ventilation channels; dispersing a potting foam into the housing in a pattern such that the potting foam reaches the plurality of air vents after substantially all of the air in the housing has passed through the air vents. Solution 1. A battery module, comprising: A housing including a sidewall structure, a top shear plate, and a bottom shear plate; A ventilation tray assembly disposed within the housing and including a cell tray and a ventilation tray, the cell tray and the ventilation tray being combined to define a plurality of ventilation channels therebetween, the cell tray including a base plate having a plurality of ventilation openings in communication with one of the plurality of ventilation channels, the ventilation tray assembly including a plurality of air vents therethrough, the plurality of air vents being isolated from the plurality of ventilation channels; A plurality of battery cells, each having an end with a vent that is aligned with one of the ventilation openings in the base plate of the cell tray; and Potting foam dispersed within the housing and between the batteries. Solution 2. The battery module according to Solution 1, wherein the cell tray includes a plurality of parallel ribs extending from the base plate of the cell tray, and the ventilation tray includes a base plate and a plurality of parallel ribs extending from the base plate of the ventilation tray, and the plurality of parallel ribs of the cell tray and the plurality of parallel ribs of the ventilation tray are combined to form the plurality of ventilation channels. Solution 3. The battery module according to Solution 1, wherein each air vent is covered with a semi-permeable medium. Solution 4. The battery module according to Solution 1, wherein the plurality of air vents are defined by a plurality of first through-holes in the cell tray and a plurality of second through-holes in the ventilation tray, the plurality of second through-holes being aligned with a corresponding one of the plurality of first through-holes in the cell tray. Solution 5. The battery module according to Solution 4, wherein the plurality of second through-holes are covered with a semi-permeable medium. Solution 6. The battery module according to Solution 4, wherein each of the plurality of through-holes in the cell tray includes a protruding portion surrounding the through-hole. Solution 7. The battery module according to Solution 4, wherein each of the plurality of through portions in the ventilation tray includes a protruding portion surrounding the through portion. Solution 8. The battery module according to Solution 4, further comprising a fitting extending between the plurality of through portions in the cell tray and the plurality of through portions in the ventilation tray. Solution 9. The battery module according to Solution 1, wherein the ventilation tray includes a base plate and a plurality of pairs of parallel ribs, and the plurality of pairs of parallel ribs are aligned with a corresponding one of the plurality of parallel ribs of the cell tray to define the plurality of ventilation channels. Solution 10. The battery module according to Solution 1, wherein the plurality of air vents are aligned on opposite sides of the ventilation passage, and the ventilation passage communicates with an opening vented to the atmosphere. Solution 11. A method of manufacturing a battery module, comprising: Inserting a plurality of battery cells into an upside-down housing having a top shear plate and a side wall structure; Placing a ventilation tray assembly on top of the battery, the ventilation tray assembly including a cell tray and a ventilation tray, the cell tray and the ventilation tray being combined to define a plurality of ventilation channels therebetween, the cell tray including a base plate having a plurality of ventilation openings communicating with one of the plurality of ventilation channels, the ventilation tray assembly including a plurality of air vents passing therethrough, the plurality of air vents being isolated from the plurality of ventilation channels; Dispensing a filling foam into the housing in a pattern such that the filling foam reaches the plurality of air vents after substantially all of the air in the housing has passed through the air vents. Solution 12. The method according to Solution 11, wherein the cell tray includes a plurality of parallel ribs extending from the base plate of the cell tray, and the ventilation tray includes a base plate and a plurality of parallel ribs extending from the base plate of the ventilation tray, and the plurality of parallel ribs of the cell tray and the plurality of parallel ribs of the ventilation tray are combined to form a plurality of ventilation channels. Solution 13. The method according to Solution 11, wherein each air vent is covered with a semi-permeable medium. Solution 14. The method according to Solution 11, wherein the plurality of air vents are defined by a plurality of first through portions in the cell tray and a plurality of second through portions in the ventilation tray, and the plurality of second through portions are aligned with a corresponding one of the plurality of first through portions in the cell tray. Solution 15. The method according to Solution 14, wherein the plurality of second through portions are covered with a semi-permeable medium. Solution 16. The method according to Solution 14, wherein each of the plurality of through portions in the cell tray includes a protruding portion surrounding the through portion. Aspect 17. The method according to Aspect 4, wherein each of the plurality of through portions in the ventilation tray includes a protruding portion surrounding the through portion. Aspect 18. The method according to Aspect 14, further comprising a fitting extending between the plurality of through portions in the unit tray and the plurality of through portions in the ventilation tray. Aspect 19. The method according to Aspect 11, wherein the ventilation tray includes a base plate and a plurality of pairs of parallel ribs, the plurality of pairs of parallel ribs being aligned with a corresponding one of the plurality of parallel ribs of the unit tray to define the plurality of ventilation channels. Aspect 20. The method according to Aspect 11, wherein the plurality of air vents are aligned on opposite sides of the ventilation passage, the ventilation passage being in communication with an opening vented to the atmosphere.

[0017] Other application areas of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present disclosure will be more fully understood from the detailed description and the drawings, wherein:

[0019] Figure 1 is a cross-sectional view of a battery pack with ventilation for a filling area according to the principles of the present disclosure;

[0020] Figure 2 is a cross-sectional view of a gas ventilation tray with ventilation for a filling area according to the principles of the present disclosure;

[0021] Figure 3 is a schematic view of a battery pack illustrating an example of a filling body dispensing position according to the principles of the present disclosure;

[0022] Figure 4 is a cross-sectional view of the battery pack showing an example of a filling body dispensing position according to the principles of the present disclosure;

[0023] Figure 5 is a schematic view of a battery pack illustrating an air ventilation system according to the principles of the present disclosure;

[0024] Figure 6 is a schematic view of a battery pack illustrating an alternative air ventilation system according to the principles of the present disclosure;

[0025] Figure 7 is a schematic view of a battery pack illustrating another alternative air ventilation system according to the principles of the present disclosure; and

[0026] Figures 8a - 8h illustrate various air ventilation passage configurations.

[0027] In the drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Description

[0028] Referring Figure 1 , a partial cross-sectional view of the battery module 10 is shown in a state that is upside down relative to its use position, for receiving a filling body, and includes an upper shear plate 12 and an integrated circuit board 14. A plurality of battery cells 16 are disposed on top of the integrated circuit board 14. A plurality of cooling bands 18 may be disposed between rows of battery cells for cooling the battery cells 16. A cell tray 20 is disposed on top of the battery cells 16 and a ventilation tray 22 engages with the cell tray 20. A bottom shear plate 24 is on top of the ventilation tray 22.

[0029] The cell tray 20 includes a base plate 26 having a plurality of ventilation openings 28 that are aligned with each battery cell 16. A mica 30 layer may be disposed between the battery cells 16 and the cell tray 20 and cover the ventilation openings 28. The cell tray 20 further includes a plurality of parallel ribs 32 extending from the base plate 26. The ventilation tray 22 includes a base plate 33 and a plurality of pairs of parallel ribs 34, each pair of which receives one of the plurality of parallel ribs 32 of the cell tray 20 therebetween. The ribs 32 of the cell tray 20 and the ribs 34 of the ventilation tray 22 combine to define a plurality of parallel ventilation channels 36 that are aligned with the plurality of ventilation openings 28. The parallel ventilation channels 36 allow each battery cell 16 to be ventilated through the mica 30 layer and the ventilation openings 28, while the ventilation channels 36 isolate the remaining battery cells 16 of the battery pack 10.

[0030] Referring Figure 1 and 2 , the cell tray 20 further includes an air through-passage 38 that is defined within the rib 32 and is aligned with a corresponding air through-passage 40 defined between the pair of ribs 34 in the ventilation tray 34. The through-passages 38 and 40 of the cell tray 20 and the ventilation tray 22 combine to define an air vent 42. A semi-permeable medium 44 layer (such as open cell foam, felt, woven or knitted fabric, non-woven fabric, paper or other selected membrane) is provided above the air vent 42 within a ventilation passage 46 that is provided between the base plate 33 of the ventilation tray 22 and the bottom shear plate 24. The air vent 42 is strategically positioned so that as the filling body surrounds and is distributed within the module 10, as the filling body expands into foam, air is pushed towards the vent. The position of the air vent 42 may be determined based on testing. Air is pushed from the bottom of the group into the vent and into the semi-permeable ventilation band 44. The air is allowed to leave the group 10 by traveling through the semi-permeable medium 44 and the ventilation passage 46.

[0031] Referring Figure 3 and4 , a battery module 10 is schematically shown, where filling body dispensing locations are illustrated at multiple locations 50 around the perimeter of the sidewall structure 51 and down a center of the housing 52. Additional dispensing locations 54 may be provided within the middle portion of the housing 52, as shown.

[0032] Referring to Figure 5 , a battery module 10 is schematically shown, where air vents 42 are positioned along opposite sides of the ventilation passage 46. The air vents 42 are covered with a semi-permeable medium 44. The air vents 42 may be staggered (as shown in the top of Figure 5 ) or aligned (as shown in the bottom of Figure 5 ). The ventilation passage 46 is connected to an opening 56 that vents to the atmosphere, and the ventilation passage 46 does not include the semi-permeable medium 44.

[0033] Referring to Figure 6 , an alternative battery module 110 is schematically shown, where air vents 42 are positioned along opposite sides of a pair of ventilation passages 46. The air vents 42 are covered with a semi-permeable medium 44. Each of the two separate ventilation passages 46 includes its own opening 56 in the ventilation tray 22, and the opening 56 vents to the atmosphere. The air vents 42 may be staggered (the top of Figure 6 ) or aligned (the bottom of Figure 6 ).

[0034] Referring to Figure 7 , an alternative battery module 210 is schematically shown, where a plurality of air vents 42 are located within a ventilation passage 246 surrounded by a gasket 248, and the ventilation passage 246 communicates with an opening 56 that vents to the atmosphere. The gasket 248 may be formed of foam dispensed in place. The air vents 42 are covered with a semi-permeable medium 44.

[0035] Figures 8(a) - 8(h) illustrate various alternative air vent geometries 42. In Figure 8(a), the conical through - portion 38 projects from the unit tray 20 and is received in the conical through - portion 40 projecting from the vent tray 22. A gasket 60 is disposed between the base plate 26 of the unit tray 20 and the distal end portion of the conical through - portion 40 of the vent tray 22. In Figure 8(b), the through - portion opening 38 is formed in the unit tray 20 and receives the distal end portion of the conical through - portion 40 projecting from the vent tray 22. In Figure 8(c), the conical through - portion 38 projects from the unit tray 20 and is received in the conical through - portion 40 projecting from the vent tray 22. A gasket 60 is disposed between the base plate 33 of the vent tray 22 and the distal end portion of the conical through - portion 38 of the unit tray 20. In Figure 8(d), the through - portion opening 38 is formed in the unit tray 20 and the conical through - portion 40 projecting from the vent tray 22 abuts against the base plate 26 of the unit tray 20. In Figure 8(e), the through - portion opening 38 is formed in the unit tray 20 and receives the distal end portion of the cylindrical through - portion 40 projecting from the vent tray 22 and snapped into the through - portion opening 38. In Figure 8(f), the through - portion opening 38 is formed in the unit tray 20 and receives a cylindrical fitting 62 having a through - portion opening 64, the through - portion opening 64 being aligned with the through - portion opening 66 in the vent tray 22. In Figure 8(g), the through - portion opening 38 is formed in the unit tray 20 and receives a cylindrical fitting 62 having a through - portion opening 64. The fitting 62 is received in the through - portion opening 66 in the vent tray 22. The fitting 62 may include a flange 68 configured to abut against the vent tray 22. As shown in Figure 8(h), the fitting 62 may include flanges 68 on both ends.

[0036] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be implemented in a variety of forms. Thus, while the disclosure includes specific examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon study of the drawings, the specification, and the appended claims. It should be understood that one or more steps within a method may be executed in a different order (or concurrently) without altering the principles of the disclosure. Additionally, while each of the embodiments above is described as having certain features, any one or more of those features described in reference to any embodiment of the disclosure may be implemented in and / or combined with the features of any one of the other embodiments, even if not explicitly described as such. In other words, the described embodiments are not mutually exclusive, and permutations of one or more of the embodiments with each other are still within the scope of the disclosure.

[0037] Various terms are used to describe spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected", "joined", "coupled", "adjacent", "next to", "on top of", "above", "below", and "disposed". Unless explicitly described as "direct", when describing the relationship between a first and a second element in the foregoing disclosure, the relationship may be a direct relationship in which no other intervening elements exist between the first and second elements, but may also be an indirect relationship in which one or more intervening elements exist between the first and second elements (spatially or functionally). As used herein, the phrase "at least one of A, B, and C" should be construed to mean a logical (A or B or C) using non-exclusive logic "or", and should not be construed to mean "at least one of A, at least one of B, and at least one of C".

Claims

1. A battery module, comprising: A housing, the housing including a sidewall structure, a top shear plate, and a bottom shear plate; A ventilation tray assembly, the ventilation tray assembly disposed within the housing and including a cell tray and a ventilation tray, the cell tray and the ventilation tray combined to define a plurality of ventilation channels therebetween, the cell tray including a base plate having a plurality of ventilation openings in communication with one of the plurality of ventilation channels, the ventilation tray assembly including a plurality of air vents therethrough, the plurality of air vents isolated from the plurality of ventilation channels; A plurality of battery cells, each having an end with a vent, the vent aligned with one of the ventilation openings in the base plate of the cell tray; And Filling foam, dispersed within the housing and between the batteries.

2. The battery module according to claim 1, wherein, The cell tray includes a plurality of parallel ribs extending from the base plate of the cell tray, and the ventilation tray includes a base plate and a plurality of parallel ribs extending from the base plate of the ventilation tray, and the plurality of parallel ribs of the cell tray and the plurality of parallel ribs of the ventilation tray combined to form the plurality of ventilation channels.

3. The battery module according to claim 1, wherein, Each air vent is covered with a semi-permeable medium.

4. The battery module according to claim 1, wherein, The plurality of air vents are defined by a plurality of first through-holes in the cell tray and a plurality of second through-holes in the ventilation tray, the plurality of second through-holes aligned with a corresponding one of the plurality of first through-holes in the cell tray.

5. The battery module according to claim 4, wherein, The plurality of second through-holes are covered with a semi-permeable medium.

6. The battery module according to claim 4, wherein Each of the plurality of through-holes in the cell tray includes a protruding portion surrounding the through-hole.

7. The battery module according to claim 4, wherein, Each of the plurality of through-holes in the ventilation tray includes a protruding portion surrounding the through-hole.

8. The battery module according to claim 4, further comprising a fitting extending between the plurality of through-holes in the cell tray and the plurality of through-holes in the ventilation tray.

9. The battery module according to claim 1, wherein, The ventilation tray includes a base plate and a plurality of pairs of parallel ribs, the plurality of pairs of parallel ribs aligned with a corresponding one of the plurality of parallel ribs of the cell tray to define the plurality of ventilation channels.

10. The battery module according to claim 1, wherein, The plurality of air vents are aligned on opposite sides of a ventilation passage, the ventilation passage in communication with an opening vented to the atmosphere.

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