DESC:TECHNICAL FIELD
[0001] The present invention relates generally to a battery assembly. More specifically, but not exclusively the present invention relates to a thermal management of the battery assembly.
BACKGROUND
[0002] Nowadays, with increasing global warming, depletion of fossil fuels, there is advancement in the technology such as an electric or hybrid electric based systems. For example, an electric vehicle or hybrid vehicles uses one or more battery packs that provides electrical power to run a motor which in turn rotates one or more wheels of the vehicle. Thus, battery pack is the energy source of electric vehicle. During vehicle driving or charging, battery generates significant amount of heat, which causes battery temperature to rise significantly. The temperature of the battery assembly is a crucial factor as high temperatures of the cells can lead to catastrophic accidents such as explosion or fire in the vehicle.
[0003] As the battery assembly generates heat while charging or discharging, it is important to limit the rise in battery temperature or extract excess heat. For safe and reliable operation of the battery, it must be maintained within the safe temperature limit, otherwise, it causes thermal runaway, which is a catastrophic failure of battery. In case of vehicle, for longer period of top speed drive, battery must be discharged at higher currents. Hence, rate of heating of cell of the battery is faster. Therefore, faster rate of cooling is necessary to keep the cells within the safe temperature operation limit. Also, once the battery is discharged, cells of the battery should be within a predefined limit, for example 50°C to enable immediate charging. So, once battery is discharged, it needs to cool down as early as possible to start recharging.
[0004] To utilize the complete capacity of battery, all the cells must be charged/discharged to same level. Sometime, because of non-uniformity of cell temperature in module, cells are discharged non-uniformly. Hence, causing voltage variation among cells of module and lower utilization of battery capacity. To avoid failure of the battery assembly, the cells of the module should be within the temperature limit. Further, if the thermal temperature of the battery assembly is not maintained, then the durability of cells of the battery will be short. In a known art, it is observed that a phase change material is filled in the internal space of battery pack. This increases overall weight of the battery assembly.
[0005] Most of the battery manufacturers and OEMs use active cooling system for battery thermal management like liquid cooling, forced air cooling or passive cooling with phase change material (PCM). Advantage of active cooling system is most used method of cooling because the battery temperature is maintained at the best performing temperature range. But the active cooling systems consume significant amount of the power from the battery assembly which in turn reduces the per charge driving range of the electric vehicle & also the cost of the system is more compared to passive cooling systems.
[0006] In case of passive cooling system with phase change material, known in the art is use of PCM material along with a container. Since it changes its phase from solid to liquid by absorbing latent heat of fusion from heat source i.e. cells of the battery, it increases the weight of the battery and eventually the vehicle.
[0007] Hence, there is a requirement for a thermal solution, which addresses the above-mentioned challenges. As per known state of art, a cooling agent such as liquid is introduced into the battery assembly. For that, separate cooling liquid coolant channels are provided. Further, additional heat transfer members must be introduced into the battery pack for cooling. This leads to the battery assembly being heavy thereby it becomes difficult to assemble, mount, dismount the battery assembly from the vehicle, etc. As per yet another known art, if heat sinks are used, thermal adhesives must be used to enhance contact between the heat sinks and the cells. Thermal adhesives are again an additional component which leads to make the battery assembly economically expensive with increased weight.
[0008] Further, in general, additional shock absorbers are also needed in conventional battery assembly to fill in gaps to prevent the pack of cells from shaking/vibrating. This adds more to the weight of the battery assembly and eventually the weight of the vehicle. Hence there is need to provide a thermal management system for a battery assembly which can overcome above said challenges of the state of art.
SUMMARY
[0009] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
[00010] Aspects of the present disclosure pertain to a battery assembly. The battery assembly comprises a plurality of cells disposed within a thermal management media within the battery assembly. The thermal management media is configured to hold the plurality of cells such that heat emanating from the plurality of cells is dissipated by the thermal management media. The thermal management media is composed of a dielectric media.
[00011] In an embodiment, the thermal management media is selected from one or more of a semi solid material such that the thermal management media solidifies beyond a predefined threshold temperature within the plurality of cells.
[00012] In an embodiment, the plurality of cells may be enveloped by a cell cover that is made of a dielectric material.
[00013] In an embodiment, the thermal management media may comprise one or more vent holes for the plurality of cells to enable escape of hot vent gases that may emanate from the cells due to extended heating.
[00014] In an embodiment, each one of the plurality of cells are connected with one another in series or parallel through an interconnector.
[00015] Further aspects of the present disclosure pertain to a battery assembly that includes a plurality of cells, a thermal management media such that the thermal management media encloses the plurality of cells. The thermal management media is a medium for extracting heat from said plurality of cells.

BRIEF DESCRIPTION OF THE DRAWINGS
[00016] The present invention is described with reference to a battery assembly, for an exemplary embodiment along with the accompanying drawings. The same numbers are used throughout the drawings to refer to similar features and components.
[00017] Fig 1 exemplarily illustrates a battery assembly with essential elements in accordance with an embodiment of the present invention
[00018] Fig 2 exemplarily illustrates a battery assembly with essential elements in accordance with an embodiment of the present invention
[00019] Fig 3 exemplarily illustrates a cell assembly with essential elements in accordance with an embodiment of the present invention
DETAILED DESCRIPTION
[00020] The present disclosure may be best understood with reference to the detailed figures and description set forth herein. Various embodiments are discussed below with reference to the figures. However, those skilled in the art will readily appreciate that the detailed descriptions given herein with respect to the figures are simply for explanatory purposes as the methods and systems may extend beyond the described embodiments. For example, the teachings presented and the needs of a particular application may yield multiple alternative and suitable approaches to implement the functionality of any detail described herein. Therefore, any approach may extend beyond the particular implementation choices in the following embodiments described and shown.
[00021] References to “one embodiment,” “at least one embodiment,” “an embodiment,” “one example,” “an example,” “for example,” and so on indicate that the embodiment(s) or example(s) may include a particular feature, structure, characteristic, property, element, or limitation but that not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Further, repeated use of the phrase “in an embodiment” does not necessarily refer to the same embodiment.
[00022] The present invention now will be described more fully hereinafter with different embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather those embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the invention to those skilled in the art.
[00023] As per an aspect of the present invention, the battery assembly comprises a plurality of cells and a thermal management media. In an embodiment, a casing may enclose the plurality of cells. The casing comprises a top portion and a bottom portion. The plurality of cells is disposed inside the casing. The thermal management media is configured to hold the plurality of cells. The thermal management media is a medium of transmitting heat from the plurality of cells to the casing. A composite thermal management material is a block which consists of thermal conductivity enhancer like graphite, ceramic etc. heat absorber like phase change material and then binding/sintering materials like graphite, epoxy etc.
[00024] As per an embodiment of the present invention, the thermal management media is extended till the casing so that direct physical connection is established between them for better conduction heat transfer to the ambient.
[00025] As per an embodiment of the present invention, the casing is configured with a fin assembly which enables active cooling of the battery assembly.
[00026] As per an embodiment of the present invention, the thermal management media is a semi solid material, being configured to solidify beyond a predefined threshold temperature.
[00027] As per an embodiment of the present invention, the plurality of cells being enveloped by a cell cover which is a dielectric material. The dielectric cover around the plurality of cells improves di-electric strength of the battery assembly and minimizes the risk of short circuit.
[00028] As per an embodiment of the present invention, the thermal management media is a block which is provided with cylindrical cut-outs. The cylindrical cut outs are almost half or less or more than the height of the cell. In an embodiment, one or more cut-outs within the block are of a cylindrical shape, with the cylindrical shape having a cross-section corresponding to shape of the plurality of cells. The plurality of cells of the battery assembly are positioned in this media. An electrical connection is made over the plurality of cells to make the battery assembly. Since, thermal management media houses the plurality of cell, it removes the requirement of additional member to hold the cells, reducing part count of battery and its weight. A cavity of the thermal management media may be cylindrical, polygonal based on cell shapes to remain good thermal contact with the cells.
[00029] As per an embodiment of the present invention, thermal management media is thermally conductive material. During charging or discharge of the battery assembly, the plurality of cells dissipate energy. Since the plurality of cells are placed in thermal management media, it effectively transfers energy from the plurality of cells to the casing of the battery assembly.
[00030] As per an embodiment of the present invention, the battery assembly comprises a plurality of cells, a thermal management media. The thermal management media is configured to hold, and shroud said plurality of cells. The thermal management media is a medium of extracting heat from the plurality of cells to the outside atmosphere. Thus, the need for a separate holder and a casing is eliminated by the present invention.
[00031] As per an embodiment of the present invention, a one or more coolant channels are designed to be integral part of the casing, whenever temperature rise is steep, coolant system is activated to remove heat dissipated from cells through the battery casing.
[00032] As per an embodiment of the present invention, a closed loop control system is devised to operate coolant system to reduce energy load on the battery assembly.
[00033] The present subject matter is further described with reference to the accompanying figures. It should be noted that the description and figures merely illustrate the 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 subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[00034] The foregoing disclosure is not intended to limit the present disclosure to the precise forms or 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 considering the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims.
[00035] Fig 1 exemplarily illustrates a battery assembly with essential elements in accordance with an embodiment of the present invention. The battery assembly (100) comprising a casing (102) having a bottom casing (102b) and a top casing (102a), a plurality of cells (104), and a thermal management media (106). The casing (102) comprises a top portion and a bottom portion. The plurality of cells (104) is disposed inside the casing (102). The thermal management media (106) is configured to hold the plurality of cells (104). The thermal management media (104) is a medium of transmitting heat from the plurality of cells (104) to the casing (102). The thermal management media is a composite material block which consists of thermal conductivity enhancer like graphite, ceramic etc. heat absorber like phase change material and then binding/sintering materials like graphite, epoxy etc. The thermal management media (106) is extended till the casing (102) so that direct physical connection is established between them for better conduction heat transfer to the ambient. The casing (102) is configured with a fin assembly (not shown) which enables active cooling of the battery assembly. The thermal management media (106) is a semi solid material, being configured to solidify beyond a predefined threshold temperature. Since the plurality of cells (104) are mounted in the thermal management media (106) which also acts as a heat dissipating element for the battery assembly (100), the need for a separated cell holder is eliminated. The plurality of cells is connected through an interconnector at a portion for being connected in series or parallel as required. The thermal management media (106) has high potential to absorb energy, when it is operated around its phase transition zone due its high latent heat of fusion. Hence, thermal management media (106) which also acts functions as a cell holder, restricts sudden rise in temperature of the battery assembly (100), during acceleration and top speed continuous drive of a vehicle (not shown). The thermal management media (106) is a composite thermal management material which does not change from solid to liquid due the binding/sintering element in the composite. Hence, ensuring the structural stability of the system. As per an embodiment of the present invention, only a part of the plurality of cells (104) height is enclosed in the composite block of the thermal management media (106). One or more vent holes (not shown) of the cells are allowed free, enabling unrestricted escape of hot vent gases. Hence, preventing bulging of cells.
[00036] As per an embodiment of the invention, the plurality of cells (104) in the battery assembly (100) are partly held by a separate cell holder made of plastic and partly by the thermal management media (106). The interconnector (108) are welded on one portion of the plurality of cells (104) to make electrical connection between the plurality of cells (104) of the battery assembly (104). To have a battery assembly (100) of higher capacity, multiple modules are placed inside the casing (102) in such a way that the thermal management media (106) butts with inner surface of casing (102).
[00037] During operation of battery assembly (100) i.e. charge or discharge of the plurality of cells (104), energy is dissipated from the plurality of cells (104), due to exothermic chemical reaction. Since, thermal management media (106) is conductive in nature, it transfers energy from heat source i.e., the plurality of cells (104) to the casing (102).
[00038] As per an embodiment of the present invention, a fins assembly is provided on external surface of the casing (102) to increase heat transfer surface area, hence, increasing cooling rate of the battery assembly (100).
[00039] Fig 2 exemplarily illustrates a battery assembly with essential elements in accordance with an embodiment of the present invention. As per an embodiment of the present invention, the thermal management media (106) can also function as bottom casing (102) cum plurality of cell (104) holder. Thus, the need for a separate cell holder and a big casing (102) is also eliminated. Thereby weight, man-hour manufacturing of said battery assembly (100) is reduced significantly.
[00040] Fig 3 exemplarily illustrates a cell assembly with essential elements in accordance with an embodiment of the present invention. The plurality of cells are being enveloped by a cell cover (300) which is a dielectric material. The dielectric cover around the plurality of cells (104) improves di-electric strength of the battery assembly (100) and minimizes the risk of short circuit. Thus, the thermal management media (106) is encapsulated with electrical insulation element i.e., the cell cover (300). The cell cover (300) is a dielectric sheet which is electrically insulative but slightly thermally conductive. Therefore, the thickness of the dielectric sheet, i.e., the cell cover (300) is maintained to reduce thermal resistivity.
[00041] The present invention provides a least thermal resistance path for conduction of heat from the plurality of cells (104) to the casing (102). The thermal management media (106) is a made such that the temperature rise of the plurality of cells (104) is slow. Hence, providing the possibility of fast charging and long period top speed drive in a vehicle.
[00042] The thermal management media (106) a least thermal resistance path for conduction of heat from the plurality of cells (104) to the casing (102) or to the atmosphere. Furthermore, the thermal management media (106) is made such that the temperature rise of the plurality of cells (104) is slow. Therefore, the present invention provides the advantage of slower heating up of the plurality of cells (104) within the battery assembly (100).
[00043] The thermal management media (106) is a made such that the temperature rise of the plurality of cells (104) is slow, and the need for a separate cell holder and a thermal management system is eliminated. thereby the weight, complexity of the battery assembly (100) is reduced. Hence, the present invention provides possibility of fast charging and long period top speed drive in a vehicle.
[00044] In some embodiments, the thermal management media (106) acts as the outer casing to the plurality of cells (104) within the battery assembly (100). This provides an advantage of reduced weight of the overall battery assembly (100) as no outer casing is required separately.
[00045] In light of the above-mentioned advantages and the technical advancements provided by the disclosed method and system, the claimed steps 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. Further, the claimed steps clearly bring an improvement in the functioning of the device (battery) itself as the claimed steps provide a technical solution to a technical problem.
[00046] Those skilled in the art will appreciate that any of the aforementioned steps and/or system modules may be suitably replaced, reordered, or removed, and additional steps and/or system modules may be inserted, depending on the needs of a particular application. In addition, the systems of the aforementioned embodiments may be implemented using a wide variety of suitable processes and system modules, and are not limited to any particular computer hardware, software, middleware, firmware, microcode, and the like. The claims can encompass embodiments for hardware and software, or a combination thereof.
[00047] While the present disclosure has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. Therefore, it is intended that the present disclosure is not limited to the particular embodiment disclosed, but that the present disclosure will include all embodiments falling within the scope of the appended claims.
List of Reference numerals
100: Battery assembly
102: Casing
102a: Top casing
102b: Bottom casing
104: Plurality of cells
106: Thermal management media
108: Interconnector
300: Cell cover
,CLAIMS:We Claim:
1. A battery assembly (100), said battery assembly (100) comprising:
a plurality of cells (104), said plurality of cells (104) being disposed within said battery assembly (100);
a thermal management media (106), said thermal management media (106) being configured to hold said plurality of cells (104);
wherein, said thermal management media (106) being a medium for dissipating heat from said plurality of cells (104).

2. The battery assembly (100) as claimed in claim 1, wherein said battery assembly (100) comprising a casing (102), said casing (102) being comprised of a top portion (102a) and a bottom portion (102b), said plurality of cells (104) being disposed within said casing (102).

3. The battery assembly (100) as claimed in claim 1, wherein said thermal management media (106) being selected from one or more of a semi solid material such that said thermal management media (106) being adapted to solidify beyond a predefined threshold temperature within said plurality of cells (104).

4. The battery assembly (100) as claimed in claim 1, wherein said plurality of cells (104) being enveloped by a cell cover (300), said cell cover (300) being composed of a dielectric material.

5. The battery assembly (100) as claimed in claim 1, wherein one or more fins being disposed on said casing (102), said one or more fins being adapted to enable dissipation of heat being transmitted through said thermal management media (106) to said casing (102).

6. The battery assembly (100) as claimed in claim 1, wherein said thermal management media (106) being a block having one or more cut-outs, said one or more cut-outs being configured to receive said plurality of cells (104).

7. The battery assembly (100) as claimed in claim 5, wherein said one or more cut-outs within said block being of a cylindrical shape, said cylindrical shape having a cross-section corresponding to shape of said plurality of cells.

8. The battery assembly (100) as claimed in claim 1, wherein said thermal management media (106) comprising one or more vent holes for said plurality of cells (104) to enable escape of hot vent gases.

9. The battery assembly (100) as claimed in claim 1, wherein each one of said plurality of cells (104) being connected with another in series or parallel through an interconnector (108).