Description:FIELD OF THE INVENTION
[0001] The present subject matter is related, in general to a thermal propagation prevention system, and more particularly, but not exclusively to a thermal propagation prevention system for a battery pack.
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BACKGROUND OF THE INVENTION
[0002] Battery pack, such as Lithium-ion (Li-ion) battery pack or the like, are used to power components in applications, such as electric vehicles, hybrid vehicles, mobile phones, laptops, medical equipment’s or the like. A battery pack has a plurality of cells in electrical connection with each other. 10
[0003] The battery pack are commonly used in various fields, for example, the battery pack serve as power sources for personal electronic devices like cell mobile phones, laptops, camera, electronic devices and the like. Further, the battery pack supplies possess desirable properties such as recharging capability, making them attractive as 15 potential power sources for automobile industry such as but not limited for automobile industry.
[0004] A lithium-ion battery is usually constituted of a positive electrode, a negative electrode, an electrolyte, and a separator. As a positive electrode active material to be 20 used for the positive electrode, lithium cobaltate, manganese spinel, or the like are mainly used. Since the positive electrode active material has a high electric resistance, the electric resistance of the positive electrode is decreased by using carbon-based conductive additives. As a binder, for example, styrene-butadiene rubber, fluororubber, synthetic rubber, a polymer such as polyvinylidene fluoride, an acryl resin, or the like 25 are used.
[0005] A negative electrode active material to be used is natural graphite, artificial graphite obtained by thermally treating coal, petroleum pitch or the like at a high temperature, amorphous carbon obtained by thermally treating coal, petroleum pitch 30 coke, acetylene pitch coke or the like, a lithium alloy such as metallic lithium or AlLi,
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or the like. Further, carbon-based conductive additives are used for a negative electrode in some cases for the purpose of decreasing the resistance.
[0006] With the advancement in technology, an electric or hybrid electric vehicle makes use of plurality of power units to drive the vehicle. Typically, the plurality of 5 power units is a battery pack to provide power to run a motor which in turn runs one or more wheels of the vehicle. The plurality of power units in such hybrid electric vehicles are prone to damage due to increase in temperature as the usage increases.
[0007] A typical battery pack comprises of a plurality of cells which are 10 interconnected in a series configuration or a parallel configuration or a combination of series and parallel configuration based on current, voltage and capacity requirements in the desired function. Battery packs are additionally sealed to improve reliability and meet waterproof and dustproof requirements.
15 [0008] During operation of battery pack when the battery pack is subjected to altitude changes and increase in temperature, which creates a difference between the internal pressure of the battery pack and the external pressure of the operating environment leading to damage caused to the sealing surface and results in battery failure. Battery heating is generally caused due to fire or explosion, chemical reactions, chemical risk 20 due to toxic liquids and gases, or short circuits.
[0009] The increase in temperature of the battery pack leads to poor performance of the vehicle and causes thermal runaway, which creates an unsafe driving condition for a user. For instance, when a cell or an area within the cell or a plurality of cells of a Li-25 ion battery pack achieves an elevated temperature due to a thermal failure or a mechanical failure or internal or external short circuiting or an electro-chemical abuse a large amount of heat is generated. When the generated heat is larger than the heat dissipation, various side reactions between the components inside the battery pack are induced. This may cause further heat generation and the pressure and the temperature 30 of the battery pack may increase sharply. This may lead to inflammation and/or explosion of the battery pack. This process is referred to as thermal runaway.
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Accordingly, during operation of the battery pack, to avoid thermal runaway and to ensure proper operation of the battery pack without failing, heat generated by each cell is to be insulated from the other cells of the battery pack.
[00010] In battery technology, lithium-ion cells have attained significant popularity due 5 to high energy density, high power density, excellent cycle performance and environmental friendliness. However, lithium-ion cells have great propensity of catastrophic failure in events of thermal runaway as the heat energy released from a single failing lithium-ion cell during thermal runaway can cause a chain reaction in the neighboring lithium-ion cells. In the case of charged Li-ion cells with high energy 10 density, the thermal runaway is a fast, violent, self-accelerating chemical reaction of electrodes and electrolyte which releases high amounts of heat and gas. A better cooled battery pack ensures the welfare and safety of the user and as well as leads to an increase in durability and health of the plurality of cells of the battery pack.
15 [00011] Existing large cell batteries are disadvantageous due to safety concerns. The energy released in the large cell of the battery that is undergoing thermal runaway is directly proportional to the amount of electrolyte available in the cell. The amount of electrolyte for large cells is substantially greater than for small cells, and large cell batteries are able to gain more momentum during thermal runaway which makes them 20 less secure. Once a large cell is in thermal runaway mode, the heat generated by the cell triggers a thermal runaway reaction in the adjacent plurality of cells, causing the battery pack to explode, with massive destruction to peripheral devices.
[00012] Conventionally, battery packs are sealed to ensure that the battery pack is 25 waterproof and dustproof, since interference of foreign particles in the battery pack may adversely affect the performance of the battery pack. However, altitude changes can affect the battery pack, causing abnormal changes in internal pressure and external pressure of the battery pack. Substantially high or low air pressure inside the battery pack may cause structural damage to the sealing surface of the battery pack, resulting 30 in battery pack failure. In addition to this, thermal runaways create a build-up of pressure and gas in the battery pack. Such pressure must be relieved to avoid damage
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and explosion due to thermal runaway. Therefore, a compromise must be met between sealing of the battery pack and relieving pressure inside the battery pack. Further, in some battery packs compression pads are provided which limit the expansion of the battery pack’s orientation due to generation of burnt gases inside the battery pack. The compression pads merely restrict the bulking of the battery packs without providing a 5 mechanism to alleviate the internal pressure of the battery pack.
[00013] Conventionally, to dissipate the heat generated in the plurality of cells of the battery pack and to overcome the thermal runaway issue, the battery pack includes liquid-filling materials, such as cooling liquid. However, use of such materials causes 10 handling problems of the battery pack. In some conventional battery packs, for managing thermal issues in battery packs have included the use of Phase Change Material (PCM) and other passive cooling techniques. The PCM absorbs the heat generated by the cells and changes its state from solid to liquid and dissipates the heat through the casing of the battery pack. However, the PCM solution is unable to dissipate 15 heat instantly in cases where thermal runaway has been triggered. Further, PCM solutions have limitations in terms of weight, mechanical stability and their ability to contain the propagation of thermal runaway and flames. Furthermore, the integration of PCM can add significant weight to the battery pack, which is undesirable in applications where weight reduction is critical for overall efficiency and performance. 20
[00014] In cases where a battery pack has been set ablaze, conventional systems fail to extinguish the fire in a timely manner. In case of failure of the existing cooling mechanisms, there is a need for systems to be adept at dousing the fire and safeguard and secure the user of the battery pack. 25
[00015] Thus, in cases where the battery pack has already reached the threshold to trigger thermal runaway, the conventional venting valves are not equipped to manage disastrous situations. Therefore, there is an additional requirement of a new kind of battery pack using which heat dissipation rate can be improved to overcome the 30 deficiency available in the art.
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[00016] The above information as disclosed in this background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
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[00017] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of described systems with some aspects of the present disclosure, as set forth in the remainder of the present application and with reference to the drawings.
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SUMMARY
[00018] The following summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described below, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 15
[00019] In one of the embodiments of the present application, a battery pack comprising a casing, plurality of cells which are placed inside the casing and each sheet of the plurality of sheets comprising plurality of slots. Further, the plurality of cells is configured to be placed in the plurality of slots. Furthermore, the plurality of slots 20 conforming with shape of the plurality of cells. In one of the embodiments of the present application, the plurality of sheets is stacked to cover length of the plurality of cells.
[00020] In one of the embodiments of the present application, the each sheet of the plurality of sheets comprising a coating of heat resistive material. Further, at least one 25 layer of silicate material is present between adjacent sheets of the plurality of sheets.In one of the embodiments of the present application, the battery pack comprising at least one cell holder comprising a top holding unit which is configured to accommodate at least one end of the plurality of cells and a bottom holding unit which is placed opposite to the top holding unit and is configured to accommodate another ends of the plurality 30 of cells. Further, space between the top holding unit and the bottom holding unit of each cell holder of the at least one cell holder is substantially equal to length of the plurality
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of cells. Furthermore, the plurality of sheets is stacked in the space between the top holding unit and the bottom holding unit of each cell holder of the at least one cell holder.
[00021] In one of the embodiments of the present application, a Phase Change Material 5 (PCM) is disposed into predefined sheets of the plurality of sheets. In one of the embodiments of the present application, the top holding unit of the at least one cell holder comprises one or more opening to allow venting of hot air gases from the plurality of cells.
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[00022] In one of the embodiments of the present application, the plurality of sheets is made from thermally insulating materials. In one of the embodiments of the present application, the plurality of slots in the each sheet of the plurality of sheets are uniformly placed. Further, the stacked sheets comprises multiple hollow slots which are formed by stacking the plurality of slots. Furthermore, the multiple hollow slots are configured 15 to accommodate the plurality of cells.
[00023] In one of the embodiments of the present application, perimeter of the multiple hollow slots is substantially equal to perimeter of the plurality of cells. In one of the embodiments of the present application, the each sheet of the plurality of sheets 20 comprises one or more openings for cell holder clamps. Further, the cell holder clamps are configured to control the compression level of the plurality of sheets.
[00024] In one of the embodiments of the present application, the each sheet (102) of the plurality of sheets ranging in thickness ranging from 1.5mm to 2.5mm. In one of 25 the embodiments of the present application, stack of the plurality of sheets is compressed between the top holding unit and the bottom holding unit of each cell holder of the at least one cell holder. Further, the each sheet of the plurality of sheets can be compressed in thickness ranging from 25% to 50% of initial thickness of the plurality of sheets. 30
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[00025] In one of the embodiments of the present application, the casing of the battery pack comprising a casing top, a casing bottom and one or more casing vertical walls. Further, the casing top and the casing bottom being connected with each other to form the casing of the battery pack. Furthermore, the casing is made of a thermally conductive material and an electrically insulating material. In one of the embodiments 5 of the present application, the casing comprises a plurality of heat dissipating fins. Further, the plurality of heat dissipating fins is disposed on an outer surface of the casing of the battery pack.
BRIEF DESCRIPTION OF THE DRAWINGS 10
[00026] The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate preferred embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain features of the invention.
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[00027] Figure 1a illustrates perspective side view of each sheet of plurality of sheets which are used in a battery pack and each sheet of plurality of sheets comprising plurality of slots to store plurality of cells.
[00028] Figure 1b illustrates perspective top view of each sheet of the plurality of 20 sheets which are used in the battery pack and each sheet of plurality of sheets comprising plurality of slots to store plurality of cells.
[00029] Figure 1c illustrates perspective left view of each sheet of the plurality of sheets which are used in the battery pack and each sheet of plurality of sheets 25 comprising plurality of slots to store plurality of cells.
[00030] Figure 1d illustrates perspective front view of each sheet of the plurality of sheets which are used in the battery pack and each sheet of plurality of sheets comprising plurality of hollow slots to store plurality of cells. 30
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[00031] Figure 2a illustrates perspective side view of the plurality of sheets which are stacked in the battery pack and the stacked sheets comprising plurality of slots to store the plurality of cells.
[00032] Figure 2b illustrates perspective top view of the plurality of sheets which are 5 stacked in the battery pack and the stacked sheets comprising plurality of slots to store the plurality of cells.
[00033] Figure 2c illustrates perspective front view of the plurality of sheets which are stacked in the battery pack and the stacked sheets comprising plurality of slots to store 10 the plurality of cells.
[00034] Figure 2d illustrates perspective left view of the plurality of sheets which are stacked in the battery pack and the stacked sheets comprising plurality of slots to store the plurality of cells. 15
[00035] Figure 3a illustrates perspective side view of the plurality of sheets which are stacked in the battery pack and the stacked sheets comprising plurality of slots to store the plurality of cells in a predefined pattern.
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[00036] Figure 3b illustrates perspective left view of the plurality of sheets which are stacked in the battery pack and the stacked sheets comprising plurality of slots to store the plurality of cells in the predefined pattern.
[00037] Figure 3c illustrates perspective front view of the plurality of sheets which are 25 stacked in the battery pack and the stacked sheets comprising plurality of slots to store the plurality of cells in the predefined pattern.
[00038] Figure 3d illustrates perspective top view of the plurality of sheets which are stacked in the battery pack and the stacked sheets comprising plurality of slots to store 30 the plurality of cells in the predefined pattern.
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DETAILED DESCRIPTION OF THE INVENTION
[00039] Exemplary embodiments detailing features of a battery pack in accordance with the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. 5 Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the present subject matter. Further, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, “primary”, “secondary”, “main” or any other 10 ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or 15 modification.
[00040] The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar elements. While embodiments may 20 be described, modifications, adaptations, and other implementations are possible. For example, substitutions, additions, or modifications may be made to the elements illustrated in the drawings, and the methods described herein may be modified by substituting, reordering, or adding stages to the disclosed methods. Accordingly, the following detailed description does not limit the claimed subject matter. Instead, the 25 proper scope of the claimed subject matter is defined by the appended claims. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present 30 subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
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[00041] Further, various embodiments disclosed herein are to be taken in the illustrative and explanatory sense and should in no way be construed as limiting of the present disclosure. All joinder references (e.g., attached, affixed, coupled, disposed, etc.) are only used to aid the reader's understanding of the present disclosure, and may not create 5 limitations, particularly as to the position, orientation, or use of the systems and/or methods disclosed herein. Therefore, joinder references, if any, are to be construed broadly. Moreover, such joinder references do not necessarily infer those two elements are directly connected to each other.
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[00042] It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Additionally, any signal hatches in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically 15 specified.
[00043] The present invention is illustrated with a power unit. However, a person skilled in the art would appreciate that the present invention is not limited to a power unit and certain features, aspects and advantages of embodiments of the present 20 invention are applicable to other forms of power units, battery packs or energy storage devices. The power unit in accordance with the present disclosure is applicable to rechargeable as well as non-rechargeable variants of power units. Further, with the initiation of electric vehicles and electric vehicles, there is a growing interest in an automotive industry to develop electrical machines which dissipate heat properly from 25 the cells of the battery pack, light in weight, utilize less space and are efficient in operation. Therefore, the direction of innovation in designing electrical machines is to develop electrical machines which have good heat dissipation, lighter in weight and compact size for a given power rating, or for a given size, power rating should be more than the present rating. 30
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[00044] It is an object of the present subject matter to provide a mechanism which can withstand high temperatures of thermal runaway and protect plurality of cells of power units or battery packs from internal pressure raises as well as regulate the flow of gases during thermal runaway. Further, the present subject matter also provides an emergency thermal management mechanism to dissipate the high temperatures of thermal runaway 5 instantly and protect the plurality of cells of power units or battery pack from exploding and causing harm to the user as well as regulate the flow of gases during thermal runaway.
[00045] Battery pack comprises a plurality of cells in electrical connection with each 10 other. During operation, each cell generates heat which is to be insulated from the other cells of the battery pack to ensure proper operation of the battery pack without failing. More specifically, battery packs, such as Lithium-ion (Li-ion) battery pack or the like, have an issue of thermal runaway. For instance, when a cell, an area within the cell, or a plurality of cells of a Li-ion battery pack achieves an elevated temperature due to a 15 thermal failure, a mechanical failure, internal or external short circuiting, or an electro-chemical abuse, a large amount of heat is generated. When the heating generated is larger than the heat dissipation, various side reactions between components inside the battery pack are induced. This may cause further heat generation and the pressure and the temperature of the battery pack may increase sharply. This may lead to 20 inflammation and/or explosion of the battery pack. This process is referred to as thermal runaway.
[00046] The present subject matter relates to heat transfer in power unit assembly such as but not limited to battery pack assemblies. With the implementations of the present 25 subject matter, heat generated by the cells of the battery pack assemblies can be efficiently insulated from the other cells of the battery pack assemblies, thereby, the thermal runaway can be eliminated.
[00047] In one of the embodiments of the present application a battery pack comprises 30 a casing to provide a cover and to provide protection to the components of the battery pack. Particularly, the casing encloses the plurality of cells 206, as shown in figure 2a,
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present inside the power unit assembly. In addition to providing cover and protecting components of the power unit assembly, the casing may facilitate dissipating the heat away from the power unit assembly to the surroundings. The power unit assembly may be a battery pack, also in the present specification the terms battery pack and power unit assembly are used interchangeably. Accordingly, in an example, the casing may be 5 made of a thermally conductive and electrically insulating material. The power unit assembly comprises a casing top and a casing bottom are connected using means available in the art. The casing top is placed opposite the casing bottom.
[00048] With reference to figures 1a to 1d, in which figure 1a illustrates a perspective 10 side view of each sheet 102 of plurality of sheets 202 which are used in a battery pack. Figure 1b illustrates perspective top view of the each sheet 102 of the plurality of sheets 202 (as shown in figure 2). Figure 1c illustrates perspective left view of each sheet 102 of the plurality of sheets 202. Figure 1d illustrates perspective front view of each sheet 102 of the plurality of sheets 202. For the sake of brevity, figures 1a to 1d are explained 15 in conjunction with each other. Each sheet 102 of the plurality of sheets 202 comprises comprising plurality of slots 104 which are configured to accommodate the plurality of cells 206. Further, the plurality of sheets 202 are provided to securely house and organize plurality of cells 206. Further, the each sheet 102 within the plurality of sheets 202 is positioned sequentially atop the other, ensuring that the plurality of slots 104 on 20 each individual sheet run parallel to one another. Furthermore, the plurality of slots 104 conforming with shape of the plurality of cells 206 in the battery pack.
[00049] In one of the embodiments of the present application, consistency is maintained in the size and dimensions of each sheet 102 across the plurality of sheets 202, with the 25 placement of the plurality of slots 104 uniformly distributed on every sheet. In one of the embodiments of the present application, the size and dimensions of each sheet 102 may be different across the plurality of sheets 202, with the placement of the plurality of slots 104 uniformly distributed on every sheet.
30 [00050] In one of the embodiments of the present application, the each sheet 102 of the plurality of sheets 202 is made from thermally insulating materials such as but not
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limited to Mica, to manage heat effectively within the battery pack. The selection of these materials helps to prevent the unnecessary transfer of heat between adjacent battery cells and ensures that temperature fluctuations are kept under control. Further, the each sheet 102 of the plurality of sheets 202 comprising a coating of heat resistive material. The incorporation of the heat-resistant material on the each sheet 102 provides 5 an additional layer of protection against heat accumulation and propagation, accordingly, enhancing the overall thermal containment capabilities of the battery pack. Furthermore, at least one layer of silicate material is present between adjacent sheets of the plurality of sheets 202. The at least layer of silicate serves as an effective insulator, contributing to the overall thermal resistance of the battery pack and further minimizing 10 heat transfer. The combination of thermally insulating materials, heat-resistant coatings, and silicate layers between the plurality of sheets 202 collectively strengthens the thermal management capabilities of the battery pack and accordingly ensuring the safety and reliable performance of the battery pack under various operating conditions and collectively minimize the likelihood of thermal events, contributing to enhanced 15 operational safety.
[00051] In one of the embodiments of the present application, the each sheet 102 of the plurality of sheets 202 ranging in thickness ranging from 1.5mm to 2.5mm. In one of the embodiments of the present application, the each sheet (102) of the plurality of 20 sheets 202 comprises one or more opening 106 for cell holder clamps. The cell holder clamps are configured for the stacking of the plurality of sheets 202. In the present specification the terms the stack of plurality of sheets 202 and the stacked sheets 202 are used interchangeably. The one or more openings in the stacked sheets 202 designed for cell holder clamps streamlines the assembly process and facilitates secure stacking, 25 ensuring consistent compression and alignment of the stacked sheets 202.
[00052] In one of the embodiments of the present application, the plurality of sheets 202 is stacked to cover length of the plurality of cells 206. In one of the embodiments of the present application, the battery pack comprises at least one cell holder. The at 30 least one cell holder in the battery pack acts as a safeguard, ensuring that the plurality of cells 206 are precisely positioned and immovably secured to prevent inadvertent
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movement, potential electrical short circuits, and potential damage during both operation and handling. The at least one cell holder comprises a top holding unit 302 which is configured to house at least one end of the plurality of cells 206, and a corresponding bottom holding unit 304 is configured to accommodate the another end of the plurality of cells 206. Further, the bottom holding unit 304 is situated in 5 opposition to the top holding unit 302 in the at least one cell holder. Furthermore, the space existing between the top and bottom holding units 302, 304 within the at least one cell holder is substantially equal to length of the plurality of cells 206 and ensuring a tailored fit.
10 [00053] Within this space existing between the top and bottom holding units 302, 304 within the at least one cell holder, the plurality of sheets 202 are seamlessly arranged and stacked. This integration of the stacked sheets 202 within the allotted space of the at least one cell holder creates an efficacious and compact solution for proficiently containing thermal propagation and constraining flame spread. In one of the 15 embodiments of the present application, the top holding unit 302 of the at least one cell holder comprises one or more opening to allow venting of hot air gases from the plurality of cells 206 to maintain the temperature and pressure inside the battery pack.
[00054] With reference to figures 2a to 2d, in which figure 2a illustrates perspective 20 side view of the plurality of sheets 202 which are stacked in the battery pack. Figure 2b illustrates perspective top view of the stacked sheets 202 comprising multiple slots 204 to store the plurality of cells 206. Figure 2c illustrates perspective front view of the stacked sheets 202 comprising multiple slots 204 to store the plurality of cells 206. Figure 2d illustrates perspective left view of the stacked sheets 202 comprising multiple 25 slots 204 to store the plurality of cells 206. For the sake of brevity, figures 2a to 2d are explained in conjunction with each other. In figure 2, 200 shows multiple slots 104 within the each sheet 102 of the plurality of sheets 202 are systematically and consistently positioned. Further, the cumulative assembly of the stacked sheets 202 results in the formation of multiple hollow slots 204. Accordingly, through the stacking 30 the individual slots 104, resulting in a unified structure of the multiple hollow slots 204. The multiple hollow slots 204 are configured to serve as designated storage place for
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the accommodation of the plurality of cells 206. Therefore, this arrangement will not only optimize the utilization of available space but also improves the functional ability of the battery pack in providing a secure and organized setting for the placement of the plurality of cells 206.
5 [00055] In one of the embodiments of the present application, perimeter of the multiple hollow slots 204 substantially equal with the perimeter measurement of the corresponding plurality of cells 206. This similarity in perimeter dimensions highlights a deliberate design consideration, ensuring a seamless and precise fit between the multiple hollow slots 204 and the plurality of cells 206. 10
[00056] In one of the embodiments of the present application, the incorporation of one or more openings 106 in each sheet 102 of the plurality of sheets 202, specifically designed to accommodate cell holder clamps. The sacked configuration of the plurality of the sheets 202 will result in a stacked one or more openings 208 in a vertically aligned 15 manner. The cell holder clamps effectively manage to arrange the plurality of sheets 202 in a precise manner, ensuring that the entire stack remains in a compressed state. This deliberate compression not only bolsters the structural integrity of the assembly but also contributes to the enhanced thermal management and safety features of the battery pack. 20
[00057] In one of the embodiments of the present application, the adjustability of compression level of the plurality of sheets 202 is seamlessly achieved through the utilization of the cell holder clamps. Accordingly, using the cell holder clamps user can control the compression level of the sheets 202 as per specific requirements, thus 25 accommodating varying thermal considerations and ensuring an optimal thermal propagation prevention mechanism. The compression level of the plurality of sheets 202 within the battery pack refers to how tightly the plurality of sheets 202 are compressed together, resulting in a reduction in their thickness.
30 [00058] In one of the embodiments of the present application, a Phase Change Material (PCM) is disposed into predefined sheets of the plurality of sheets 202 which will
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further contribute to the overall thermal resistance of the battery pack and further minimizing heat transfer. The combination of the stacked sheets 202 and optional integration of PCM offers a balanced approach to cooling. It allows for efficient heat dissipation while also absorbing and releasing heat when necessary, contributing to temperature regulation. 5
[00059] In one of the embodiments of the present application, the stacked sheets 202 are compressed. This compression occurs within the confined space between the top holding unit 302 and the corresponding bottom holding unit 304 of each cell holder of the at least one cell holder. This configuration ensures that the individual sheets 102 10 constituting the stack experience a controlled reduction in their thickness, ranging from 25% to 50% of their initial thickness. The controlled compression within this range optimizes the interaction between the plurality of sheets 202, influencing factors such as heat transfer, thermal insulation, and the overall structural integrity of the battery pack, thereby contributing to enhanced performance. 15
[00060] With reference to figures 3a to 3d, in which figure 3a illustrates perspective side view of the stacked sheets 202 comprising plurality of slots 204 to store the plurality of cells 206 in a predefined pattern. Figure 3b illustrates perspective left view of the stacked sheets 202 comprising plurality of slots 204 to store the plurality of cells 20 206 in the predefined pattern. Figure 3c illustrates perspective front view of the stacked sheets 202 comprising plurality of slots 204 to store the plurality of cells 206 in the predefined pattern. Figure 3d illustrates perspective top view of the stacked sheets 202 comprising plurality of slots 204 to store the plurality of cells 206 in the predefined pattern. For the sake of brevity, figures 3a to 3d are explained in conjunction with each 25 other. In an illustrative exemplary embodiment as depicted in Figure 3, 300 highlights the manner in which one end 206a and another end 206b of the plurality of cells 206 are positioned within the array of multiple hollow slots 204 present in the plurality of sheets 202. This strategic arrangement optimizes the fit of the plurality of cells 206, creating a secure and organized assembly that aids in the containment of thermal 30 propagation and ensures structural stability. Further, the stacked sheets 202 is appropriately positioned between the top holding unit 302 and the bottom holding unit
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304 of the at least one cell holder. Accordingly, the stacked sheets 202 in strengthening the overall structural integrity and thermal management capabilities of the battery pack. Furthermore, 300 provides a glimpse into the presence of stacked openings 208 which are aligned in a vertical orientation. This alignment synchronizes with the configuration of the cell holder clamps, enhancing the efficiency of the stacking process while 5 ensuring the assembly remains securely compressed.
[00061] A person with ordinary skills in the art will appreciate that the systems, modules, and sub-modules have been illustrated and explained to serve as examples and should not be considered limiting in any manner. It will be further appreciated that 10 the variants of the above disclosed system elements, modules, and other features and functions, or alternatives thereof, may be combined to create other different systems or applications.
[00062] The present invention is having the ability to contain thermal propagation. 15 More specifically, by employing a stack of thermally insulating sheets, each coated with a layer of heat-resistant material, the invention effectively curtails the spread of thermal runaway and the potential for flame propagation. Further, incorporation of the stacked sheets not only enhances the overall robustness of the assembly but also contributes to the longevity and resilience of the battery pack. This mechanical stability fortifies the 20 pack against various external stresses and operational conditions, guaranteeing sustained performance over time. The stack of sheets allows for customization of the compression levels, facilitating tailored thermal management strategies to suit specific requirements. This adaptability ensures efficient heat dissipation while also accommodating the absorption and release of heat as needed, resulting in optimized 25 temperature regulation. Furthermore, one of the problems pertaining to weight of the battery pack, is appropriately addressed by the elimination of PCM and the adoption of the stack of sheets. This reduction in weight and bulkiness contributes to improved overall efficiency and extended operational range in case of electronic vehicles.
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[00063] In view of the above, the present invention as discussed above are not routine, conventional, or well understood in the art, as the claimed steps enable the following solutions to the existing problems in conventional technologies.
[00064] The above-described embodiments, and particularly any “preferred” 5 embodiments, are possible examples of implementations and merely set forth for a clear understanding of the principles of the invention. It will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention.
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[00065] Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. It should be appreciated that the following figures may not be drawn to scale.
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[00066] The foregoing disclosure is not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the 20 art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.
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[00067] In the foregoing specification, the disclosure has been described with reference to specific embodiments. However, as one skilled in the art will appreciate, various embodiments disclosed herein can be modified or otherwise implemented in various other ways without departing from scope of the disclosure. Accordingly, this description is to be considered as illustrative and is for the purpose of teaching those 30 skilled in the art the manner of making and using various embodiments of the disclosure. It is to be understood that the forms of disclosure herein shown and
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described are to be taken as representative embodiments. Equivalent elements, materials, processes or steps may be substituted for those representatively illustrated and described herein. Moreover, certain features of the disclosure may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the disclosure. Expressions such as 5 “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. , C , C , Claims:We Claim:
1. A battery pack, the battery pack comprising:
a casing;
a plurality of cells (206), the plurality of cells (206) is placed inside the 5 casing; and
a plurality of sheets (202), each sheet (102) of the plurality of sheets (202) comprising plurality of slots (104),
wherein the plurality of cells (206) is configured to be placed in the plurality of slots (104), and 10
wherein the plurality of slots (104) conforming with shape of the plurality of cells (206).
2. The battery pack as claimed in claim 1, wherein the plurality of sheets (202) is stacked to cover a length of the plurality of cells (206). 15
3. The battery pack as claimed in claim 1, wherein the each sheet (102) of the plurality of sheets (202) comprising a coating of heat resistive material and at least a layer of silicate material is present between adjacent sheets of the plurality of sheets (202). 20
4. The battery pack as claimed in claim 1, wherein the battery pack comprising at least one cell holder, the at least one cell holder comprising:
a top holding unit (302), the top holding unit (302) is configured to accommodate at least one end of the plurality of cells (206); and 25
a bottom holding unit (304), the bottom holding unit (304) is placed opposite to the top holding unit (302) and is configured to accommodate another ends of the plurality of cells (206),
wherein a space between the top holding unit (302) and the bottom holding unit (304) of each cell holder of the at least one cell holder is equal to 30 length of the plurality of cells (206); and
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the plurality of sheets (202) is stacked in the space between the top holding unit (302) and the bottom holding unit (304) of each cell holder of the at least one cell holder.
5. The battery pack as claimed in claim 4, wherein a Phase Change Material 5 (PCM) is disposed into predefined sheets of the plurality of sheets (202).
6. The battery pack as claimed in claim 4, wherein the top holding unit (302) of the at least one cell holder comprises one or more opening to allow venting of hot air gases from the plurality of cells (206). 10
7. The battery pack as claimed in claim 4, wherein the plurality of sheets (202) is made from thermally insulating materials.
8. The battery pack as claimed in claim 4, wherein the plurality of slots (104) in 15 the each sheet (102) of the plurality of sheets (202) are uniformly placed, wherein the stacked sheets (202) comprises multiple hollow slots (204), the multiple hollow slots (204) is formed by stacking the plurality of slots (104); and the multiple hollow slots (204) are configured to accommodate the plurality of cells (206). 20
9. The battery pack as claimed in claim 1, wherein perimeter of the multiple hollow slots (204) is equal to perimeter of the plurality of cells (206).
10. The battery pack as claimed in claim 1, wherein the each sheet (102) of the 25 plurality of sheets (202) comprises one or more openings (106) for cell holder clamps and wherein the cell holder clamps are configured to control the compression level of the plurality of sheets (202).
11. The battery pack as claimed in claim 1, wherein the each sheet (102) of the 30 plurality of sheets (202) ranging in thickness ranging from 1.5mm to 2.5mm.
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12.The battery pack as claimed in claim 1, wherein stack of the plurality of sheets(202)is compressed between the top holding unit (302) and the bottom holdingunit (304) of each cell holder of the at least one cell holder, and wherein the each sheet (102) of the plurality of sheets (202) can be compressed in thickness ranging from 25% to 50% of initial thickness of the plurality of sheets (202). 5
13.The battery pack as claimed in claim 1, wherein the casing of the battery packcomprises:
a casing top;
a casing bottom; and 10
wherein the casing top and the casing bottom is placed opposite to each other; and
wherein the casing is made of a thermally conductive and electrically insulating materials.
15
14.The battery pack as claimed in claim 1, wherein the casing comprises a pluralityof heat dissipating fins; and wherein the plurality of heat dissipating fins isdisposed on an outer surface of the casing of the battery pack.