Description:FIELD
The present disclosure generally relates to the field of rechargeable electrical energy storage systems (REESS) and their venting mechanisms.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Battery packs, particularly those used in applications such as electric vehicles and their energy storage systems, are prone to safety risks arising from Thermal Runaway (TR) events. Venting is an important safety feature in lithium-ion cells that relieves internal pressure generated by overcharging or thermal runaway. Controlled venting by rupture disks or pressure relief valves reduces dangers, but uncontrolled venting can be hazardous, releasing flammable gases, poisonous fumes, and high-temperature particles, perhaps leading to a battery pack fire or explosion. Proper venting design is essential for ensuring safety, increasing battery life, and preventing harmful incidents in high-energy applications.
A Thermal Runaway in one cell of a module can escalate into a critical situation, especially when battery modules are arranged with their vents facing each other. This configuration increases the likelihood of vent gases from the affected cell impacting the opposite module, leading to several adverse consequences. Firstly, vent gases can cause a Thermal Runaway in the opposite cell, resulting in propagation of the thermal event, which may cause severe damage to the battery, the vehicle, or even pose life-threatening risks. Secondly, the force and heat generated by vent gases can compromise the integrity of the battery casing, leading to failure of the battery enclosure at its weakest point. Lastly, vent openings often fail to function as intended due to insufficient pressure build-up near their location, resulting from uneven pressure distribution within the battery pack. When the required vent opening pressure is not met, the gases remain trapped, increasing the risk of enclosure rupture at unintended zones.
Additionally, improper venting design poses risks even in configurations where battery modules do not face each other. In such cases, inefficient vent placement can result in reduced pressure at the vent location, preventing proper gas expulsion and leading to hazardous pressure accumulation.
Existing battery pack designs lack mechanisms to effectively isolate modules from one another or manage vent gas dynamics during a Thermal Runaway event, whether modules face each other or not. These limitations result in uncontrolled gas propagation, delayed vent membrane rupture, and reduced reliability of vent openings, significantly compromising battery safety.
Therefore, there is felt a need for a battery venting and diffusion assembly for an electric vehicle that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a battery venting and diffusion assembly for an electric vehicle.
Another object of the present disclosure is to provide a battery venting and diffusion assembly that can isolate adjacent modules facing each other to prevent Thermal Runaway propagation.
Yet another object of the present disclosure is to provide a battery venting and diffusion assembly that optimizes vent gas diffusion.
Still another object of the present disclosure is to provide a battery venting and diffusion assembly that improves pack vent reliability by increasing the pressure near the vent location helping it rupture earlier and increasing the degas flow rate.
A further object of the present disclosure is to provide a battery venting and diffusion assembly that enhances safety and minimizes the risk of damage to the battery pack and its surroundings.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a battery venting and diffusion assembly for an electric vehicle. The assembly is configured for a battery pack which comprises a battery enclosure provided with a pack vent sealed by a pack vent membrane. The battery enclosure is configured to nest a plurality of cells having cell vents configured thereon for expelling cell vent gases.
The assembly comprises at least one separator plate configured to be positioned adjacent to a cell, proximal to the cell vents, at an angle inclined to an operative longitudinal plane of the cell. The assembly further comprises a plurality of diffusers mounted on the separator plate coaxial to the cell vents at a spaced-apart distance from a corresponding cell vent. The diffusers are configured to facilitate diffusion of vent gases impinging thereon, and decrease the velocity of the vent gas expelled to increase the static pressure. Additionally, the assembly includes a plurality of partition walls provided on the separator plate along an operative longitudinal axis of the separator plate. The partition walls are configured to guide the diffused vent gases towards the pack vent. The diffuser assembly is configured to facilitate an increase in the flow rate of vent gases towards the pack vent and enable relatively early rupture of the pack vent membrane for expelling vent gases through the pack vent.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A battery venting and diffusion assembly, of the present disclosure, for an electric vehicle will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates an isometric view of a first embodiment of the assembly of the present disclosure;
Figure 1A illustrates a top view of the first embodiment of the assembly of the present disclosure;
Figure 2 illustrates an isometric view showing the vent gas flow through the assembly of Figure 1;
Figure 3 illustrates an isometric view of a second embodiment of the assembly of the present disclosure;
Figure 4 illustrates an isometric view showing the vent gas flow through the assembly of Figure 3;
Figure 5 illustrates an isometric view of a base plate used for a first type of cells, with slots provided thereon for mounting diffusers thereon;
Figure 5A illustrates isometric views of the diffusers for the first type of cells;
Figure 6 illustrates an isometric view of a base plate used for a second type of cells, with slots provided thereon for mounting diffusers thereon;
Figure 6A illustrates isometric views of the diffusers for the second type of cell;
Figure 6B illustrates a front view of a diffuser;
Figure 7 illustrates a top view of the assembly of Figure 1;
Figure 8 illustrates a top view of the assembly of Figure 7 showing the diffusion of the vent gas after impinging on the diffuser;
Figure 9 and Figure 10 illustrate isometric views of cells (both the first type and the second type of cells) disposed on the assembly of Figure 1;
Figure 11 illustrates an exploded view of a battery pack;
Figure 12 illustrates a side view of the assembly and the cells;
Figure 13 illustrates the pressure vs time graph representing the time required to enable rupture of the pack vent membrane for expelling vent gases;
Figures 14A through 14C illustrate pressure distribution of vent air domain after the cells are triggered to release vent gas with and without this separator assembly; and
Figures 15A through 15C illustrate velocity distribution after the cells are triggered to release vent gas with and without this separator assembly.
LIST OF REFERENCE NUMERALS
10 battery enclosure
20A, 20B cell
25 pack vent
100 battery vent diffuser assembly
105A, 105B separator plate
106 base
107 side wall
108 mouth
109 slot
110A, 110B diffuser
115 partition wall
117 mounting
X angle
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units, and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
A battery venting and diffusion assembly (100), of the present disclosure, for an electric vehicle will now be described in detail with reference to Figure 1 through Figure 15C.
The battery vent diffuser assembly (100) (hereinafter referred to as ‘the assembly (100)’) is configured for a battery pack of the vehicle. The battery pack comprises a battery enclosure (10) provided with a pack vent (25) sealed by a pack vent membrane (shown in Figure 11). The battery enclosure (10) is configured to nest a plurality of cells (20) having cell vents (not shown in figures) configured thereon for expelling cell vent gases therefrom.
Figure 1 illustrates the assembly (100). The assembly (100) comprises at least one separator plate (105A, 105B) configured to be positioned adjacent to a cell (20), proximal to the cell vents, at an angle inclined to an operative longitudinal plane of the cell. A plurality of diffusers (110A, 110B) is mounted on the separator plate (105A, 105B) coaxial to the cell vents at a spaced apart distance from a corresponding cell vent (as shown in Figure 2 and Figure 3). The diffusers (110A, 110B) are configured to facilitate diffusion of vent gases impinging thereon, and decrease the velocity of the vent gas expelled to increase the static pressure.
The inclined positioning of the separator plate (105A, 105B) is designed to optimize the direction and flow of vent gases discharged from the cell vents. The discharged vent gas expelled from the cell vents interacts with the diffusers (110A, 110B) (as shown in Figure 8) to facilitate the diffusion of the gases as they impinge on the diffusers (110A, 110B). The diffusers (110A, 110B) help in expansion of gases when impinged thereon, and reduces velocity of the gases, thereby reducing the dynamic impact of ejected particles. This diffusion process reduces the impact of the vent on the separator, while maintaining a streamlined flow, ensuring uniform and controlled gas expulsion.
In case of a contrary scenario, other cells can come in contact with Thermal Runway gases and trigger a secondary combustion in the battery pack which can risk the safety of the pack.
A plurality of partition walls (115) is provided on the separator plate (105A, 105B) along an operative longitudinal axis of the separator plate (105A, 105B), as shown in Figure 1 and Figure 2. The partition walls (115) create discrete channels for the passage of the diffused gases. The partition walls (115) are configured to guide the diffused vent gases towards the pack vent (25) along a directed path, as shown in Figure 1A, towards the pack vent (25). By creating the directed path, the partition walls (115) prevent lateral dispersion of vent gases and ensure that the flow remains concentrated and efficiently directed.
The diffuser assembly (100) is configured to help reduce the impact of vent gases on the separator plate (105) and make the gases to flow inside the vanes and towards the pack vent, thereby allowing increase in the localized pressure near the pack vent to enable relatively early rupture of the pack vent membrane for expelling vent gases through the pack vent (25). More specifically, the inclination of the separator plate (105A, 105B) provides a direct and guided path for vent gases to travel efficiently from the cell vents towards the pack vent, reducing turbulence and resistance in the gas flow. Further, the channels created by the partition walls (115) prevent the gases from spreading laterally and ensure that the flow remains directed towards the pack vent (25). This guided flow minimizes backflow or gas stagnation, improving overall flow dynamics. The controlled diffusion and channelling of gases reduce the pressure build-up within the battery pack. Moreover, the reduction in backpressure enhances the velocity of gases flowing toward the pack vent (25). The improved flow rate results in a quicker build-up of localized pressure at the pack vent membrane. This enables relatively early rupture of the membrane, allowing vent gases to escape promptly through the pack vent (25).
In an embodiment, as shown in Figure 1 and Figure 3, the separator plate (105A, 105B) is defined by a base (106), side walls (107) extending from the base (106) and configured to abut the battery pack. The separator plate (105A, 105B) includes a mouth (108) configured on the side walls (107) at an operative front edge of the separator plate (105A, 105B) complementary to the pack vent (25). Vent gas guided through by the partition walls (115) is allowed to flow through the mouth (109) to the pack vents (25).
In another embodiment, the separator plate (105A, 105B) includes a plurality of mountings (117) configured on operative edges thereof, as shown in Figure 1, for connecting the separator assembly to a cell holder. The mountings (117) are of varying height. The mountings (117) are configured to be arranged in an ascending order of height from an operative rear edge of separator plate (105A, 105B) to the mouth (109) to facilitate inclined orientation of the separator plate (105A, 105B).
In an embodiment, the separator plate (105A, 105B) is configured to be inclined at an angle ranging between 1° and 3° relative to the operative longitudinal plane of the cells (20) to optimize the directional flow of vent gases toward the pack vent (25).
In an embodiment, the diffusers are of frustum-shaped configuration (110A) (as shown in Figure 1) or have triangular configuration (110B) (as shown in Figure 3). This configuration is designed to optimize the interaction between vent gases and the diffuser (110A, 110B) surface, enhancing the diffusion process by effectively breaking down the high-velocity gas streams.
In an embodiment, the diffusers (110A) have a solid-body configuration. In another embodiment, the diffusers (110A) have a perforated configuration (as seen in Figure 3 and Figure 4) configured to facilitate the vent gases to flow through said perforations.
In one embodiment, the separator plate (105A, 105B) includes a plurality of slots (109) configured thereon at a spaced apart distance from each other. In another embodiment, the separator plate (105A, 105B) can be used for cells of different sizes, using diffusers of different sizes and different placements based on the cell layout, as shown in Figure 5 and Figure 6.
Figure 5 shows a separator plate provided with slots configured thereon for mounting diffusers (as shown in Figure 5A) corresponding to a first type of cells. Figure 6 shows a separator plate provided with slots configured thereon for mounting diffusers (as shown in Figure 6A) corresponding to a second type of cells. The assembly (100) can be employed for multiple cell sizes and different cell chemistries while keeping the base plate common, and using diffusers of the desired configuration. The diffusers can be detachably put in the slots based on the positions as per the cell layouts. This commonization of the base plate will lead to saving cost when multiple cell sizes need to be used.
In another embodiment, each of the diffuser (110A, 110B) includes a locking means configured to facilitate detachable mounting of the diffuser (110A, 110B) in the slot.
In an embodiment, the diffuser (110A, 110B) may include a snap-fit locking mechanism defined by a flexible protrusion or tab provided on the diffuser, and configured to be snapped into the slot. In another embodiment, the locking means may be a bayonet lock, a threadable fastener, locking clip, a key, or a hook and latch mechanism. In yet another embodiment, the locking means may include ridges that create a tight fit when pressed into the slot.
In an embodiment, the frustum angle (X) of each of the diffuser (110A, 110B) ranges between 15° to 30° (as shown in Figure 6B).
In an embodiment, each of the partition wall (115) has a wedge-shaped configuration configured to taper from the mouth (109) end of the separator plate (105A, 105B) to its operative rear edge. The inclined wedge-shaped configuration of the walls helps in defining pressure zones within the assembly (100) for limiting pressure build-up of vent gases therein. The partition walls (115) are further configured to restrict the flow of vent gases therebetween and direct the gases towards pack vent, without allowing the gases to spread to a larger volume, thereby reducing any risk.
In an embodiment, the separator plate (105A, 105B), the diffusers (110A, 110B) and the partition walls (115) are of a flame-retardant material selected from the group consisting of polypropylene (PP), polycarbonate-acrylonitrile butadiene styrene (PC-ABS), polyamide (PA6), aluminium or any other suitable flame-retardant material .
In an operative configuration, the assembly (100) is configured to receive a cell pack module as shown in Figure 10. In another operative configuration, the assembly (100) is configured to be disposed between two cell pack modules (20) as shown in Figure 11.
Figure 13 illustrates the pressure vs time graph representing the time required to enable rupture of the pack vent membrane for expelling vent gases through the pack vent (25). It can be concluded from the graph that the rupture of the pack vent membrane is facilitated faster with the assembly (100) of the present disclosure, and the vent opening time is reduced by 50%, i.e., from 2 seconds to 1 second.
Figures 14A through 14C illustrate pressure distribution of vent air domain after the cells are triggered to release vent gas without and with the assembly (100). As seen in Figure 14A, vent gas in a battery pack without assembly (100) hits the outer module, thereby increasing the risk of propagation to the opposite cell. Moreover, without the assembly (100) there is recirculation in vent gas flow which delays the vent opening and in with assembly (100) the flow is directed towards the vent. On the other hand, as seen in Figure 14C, the pressure at the vent location is more in case provided with the assembly (100) when compared to a case without the assembly (100). This allows the membrane of the vent to rupture early and degas early without reaching the enclosure rupture limit.
Figures 15A through 15C illustrate velocity distribution of vent air domain after the cells are triggered to release vent gas without and with the assembly (100). In case of the modules provided with the assembly (100), as shown in Figure 15C, the velocity of the vent gases exiting is relatively higher, which leads to early degassing enhancing the overall safety of the battery pack.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to a battery venting and diffusion assembly for an electric vehicle, that:
● can isolate adjacent modules facing each other to prevent Thermal Runaway propagation;
● optimizes vent gas diffusion;
● improves pack vent reliability by increasing the pressure near the vent location helping it rupture earlier and increasing the degas flow rate; and
● enhances safety and minimizes the risk of damage to the battery pack and its surroundings.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, or group of elements, but not the exclusion of any other element, or group of elements.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. , Claims:WE CLAIM:
1. A battery venting and diffusion assembly (100) for an electric vehicle having a battery pack comprising a battery enclosure (10) provided with a pack vent (25) sealed by a pack vent membrane, wherein the battery enclosure (10) is configured to nest a plurality of cells (20) having cell vents configured thereon for expelling cell vent gases, said assembly (100) comprising:
● at least one separator plate (105A, 105B) configured to be positioned adjacent to a cell (20), proximal to the cell vents, at an angle inclined to an operative longitudinal plane of the cell;
● a plurality of diffusers (110A, 110B) mounted on said separator plate (105A, 105B) coaxial to the cell vents at a spaced apart distance from a corresponding cell vent, said diffusers (110A, 110B) configured to facilitate diffusion of vent gases impinging thereon and decrease the velocity of the vent gas expelled to increase the static pressure; and
● a plurality of partition walls (115) provided on said separator plate (105A, 105B) along an operative longitudinal axis of the separator plate (105A, 105B), said partition walls (115) configured to guide the diffused vent gases towards the pack vent (25) to enable relatively early rupture of the pack vent membrane for expelling vent gases through the pack vent (25).
2. The assembly (100) as claimed in claim 1, wherein said separator plate (105A, 105B) is defined by a base (106), and side walls (107) extending from said base (106) and configured to abut the battery pack, said separator plate (105A, 105B) having a mouth (109) configured on said side walls (107) at an operative front edge thereof 105A, 105B complementary to the pack vent (25),
wherein, vent gas guided through by said partition walls (115) is allowed to flow through said mouth (109) to the pack vents (25).
3. The assembly (100) as claimed in claim 1, wherein said separator plate (105A, 105B) is configured to be inclined at an angle ranging between 1° and 3° relative to the operative longitudinal plane of the cells (20) to optimize the directional flow of vent gases toward the pack vent (25).
4. The assembly (100) as claimed in claim 1, wherein said diffusers are of frustum-shaped configuration (110A) or triangular configuration (110B).
5. The assembly (100) as claimed in claim 1, wherein said diffusers (110A) have a solid-body configuration.
6. The assembly (100) as claimed in claim 1, wherein said separator plate (105A, 105B) includes a plurality of slots (109) configured thereon at a spaced apart distance from each other.
7. The assembly (100) as claimed in claim 7, wherein each of said diffuser (110A, 110B) includes a locking means configured to facilitate detachable mounting of said diffuser (110A, 110B) in said slot.
8. The assembly (100) as claimed in claim 1, wherein the frustum angle (X) of each of said diffusers (110A, 110B) ranges between 15° to 30°.
9. The assembly (100) as claimed in claim 1, wherein each of said partition wall (115) has a wedge-shaped configuration configured to taper from the mouth (109) end of said separator plate (105A, 105B) to its operative rear edge, to define pressure zones within said assembly (100) for limiting pressure build-up of vent gases therein, said partition walls further configured to restrict the flow of vent gases therebetween.
10. The assembly (100) as claimed in claim 1, wherein said separator plate (105A, 105B), said diffusers (110A, 110B) and said partition walls (115) are of a flame-retardant material selected from the group consisting of polypropylene (PP), polycarbonate-acrylonitrile butadiene styrene (PC-ABS), polyamide (PA6), or aluminium.

Dated this 13th Day of February 2025

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
OF R. K. DEWAN & CO.
AUTHORIZED AGENT OF APPLICANT

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI