FIELD OF THE INVENTION

The present subject matter relates to electrical energy storage devices and interconnect systems for automotive, on/off-grid energy storage, portable energy devices and manufacturing fields, and more particularly to a battery pack casing.

BACKGROUND OF THE INVENTION

This section is intended to provide information relating to the field of the invention and thus any appro ach/functionality described below should not be assumed to be qualified as prior art merely by its inclusion in this section.

Embodiments of a present disclosure relate to energy storage device’ s outer casing for a battery pack to enclose and protect the battery pack from damaging due to physical and thermal impact. Further the present disclosure also relates to enhancement of safety of personnel during assembly and service by activation of the electrical interconnect mechanism in the battery pack upon assembly.

Rechargeable batteries ae high on demand in this era of fast-paced lifestyle. The worldwide demand for battery is driven by automotive starter batteries, portable computers and mobile phones, high-power applications like electric vehicles (EV) etc. . .Depending on the application and usage of battery there is need for certain aspects to be met. Firstly, from the perspective of the consumer to meet the demand of the application. For example, in case of EV, the duration of operability, the charging time, number of charge cycles, serviceability, prevention of damage due to physical impact etc. .. Secondly, from the perspective of design and manufacturing to provide optimum output, efficient operation, optimum size and weight for the application, maximizing energy density of the battery pack, prevention of damage due to thermal runaway, efficient cooling, reduction of cost and steps involved in assembly process, safety of assembly/manufacturing and service personnel, prevention of physical damage due to impact, serviceability by enabling swapping of one or more damaged battery cells etc. . .

In the designing of a battery pack, therefore, packaging/protective casing is one such crucial aspect that can be used to solve some of the problems as listed above.

A cell is a fundamental building block of a battery pack for energy storage and is used in Electric Vehicles, On/Off-grid energy storage systems, telecommunication devices, portable energy devices etc. A cylindrical cell consists of a positive electrode on the top surface and negative electrodes on the bottom surfaces of the cell. These electrodes are called 'Cell tabs' and are the points to which connections are made. A battery pack is an electrical energy source using a plurality of the above-said cells in which the tabs of a plurality of the cells are connected in series and parallel connected arrays, that are electromechanically connected to current carrying conductors that provide an electrical output of voltage and current.

Current battery pack designs have low and inefficient cooling effectiveness of individual cylindrical energy storage units in battery systems that result in thermal runaway condition, causing fires. Individual Cell temperatures throughout the battery pack are not uniform throughout all cells, which reduce cycle life of pack due to non-uniform temperature gradient. Further, typical battery packs have low passive cooling capacity of battery packs due to design and layout of outer casing, Structural integrity of swappable/removable packs which are prone to vibrations, noise and impact. The other limiting issue for a lithium-ion batteries is safety. Lithium-ion batteries are very sensitive to overcharge and high temperature. At temperatures above 70°C, unfavourable heatproducing side reactions inside the battery cell can lead to even further increases in the battery cell temperature. The battery cell internal temperature increases rapidly if heat is not dissipated effectively. Thermal runaway is triggered by portions of the battery cell reaching critical temperatures that cause the onset of heat-producing exothermic reactions. Internal short circuiting can lead to rapid temperature rises in an individual battery cell leading to a thermal runaway, and the temperature increase in one cell can propagate to other nearby cells in a battery pack, thus causing them to rapidly self-heat, too leading to a cascading effect of thermal runaway propagation. Furthermore, the energy released from these reactions can be significant and dangerous.

Use of extra cooling channels carrying coolant-like substances or large heat sinks, reduces the energy density of pack and add more weight to the battery pack, making it very tough to be used as a swappable battery pack unit and particularly in a in an application for example like usage in two-wheeler EVs where the space is limited and the weight of the battery is required to be reduced for operational energy efficiency of the EV.

Further, there is need for thermal management schemes and devices that mitigate or counteract a rapid temperature rise triggered by thermal runaway to improve the safety of high energy battery packs. Mere usage of safety gloves/insulated clothing by technicians/assembly line workers while assembling battery pack, is not a fail proof method for worker/human safety.

Further usage of heavy machinery to assemble the pack, while a human-personnel is working with a ‘live’ battery pack could even endanger life of the worker/technician attending to the pack.

There is also an option of using fasteners in connecting these energy storage devices’ tabs’ together to a bus-bar to provide a simple assembly process of these cells that do not involve costly welding equipment as well as non-heat generating cell joining processes. But these mechanical assemblies are often too large and involve adding many fasteners which add towards the weight of the pack and make them bulky compared to conventional battery packs made with welding processes, which prevent fastener's to be used in a compact space such as an electrically powered two-wheeler.

Hence, there is a need for an improved battery casing for safety of the assembly personnel/ a user and improve serviceability of the battery pack during accident/scheduled maintenance. Further there is need for better thermal management for optimum and long-term operability of the battery pack which addresses the aforementioned issues. Further there is need to reduce the bulk/weight of the battery pack.

OBJECTIVE OF THE INVENTION

An object of the present invention is to provide a solution for more robust battery casings that prevent the individual energy storage units from any physical and thermal impact.

Another object of the present invention is to reduce the weight/bulk of the battery pack and improve the energy density to enable usage of the same in smaller systems.

Another object of the present invention is to also reduce the processes in battery pack assembly. Another object of the present invention is to also improve the serviceability of the pack, allowing individual energy storage units to be replaced in case of failure during the operational life-cycle of the pack in all its use cases.

Another object of the present invention is to also achieve a better overall safety of the user/technician by keeping the pack’s main output de-activated until the below said invention’s embodiments are applied.

Another object of the present invention is to provide an effective cooling/heat extraction solution from individual energy storage devices in a battery pack using a plurality of energy storage devices by cooling/extracting heat from each of the individual tabs corresponding to each of the plurality of energy storage devices.

Another object of the present invention is to reduce the risk of thermal runaway of the individual energy storage devices via its tabs, thus increasing the overall safety of the battery pack.

Another object of the present invention is to increase life-cycle of the individual energy storage systems by virtue of maintaining consistent temperature gradient throughout the energy storage device.

SUMMARY OF THE INVENTION:

One or more shortcomings of the conventional systems are overcome by system as claimed and additional advantages are provided through the provision of system and method as claimed in the present disclosure. Additional 5 features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

The present invention relates to a battery pack casing to encase and protect a plurality of energy storage devices, particularly with an objective to prevent/reduce bulk and weight of the battery pack, improve serviceability and achieve better safety by keeping the battery packs main output de-activated until the casing is closed. The invention addressed the problems of cooling individual energy storage devices, reduction of assembly process steps, improving safety of manual assembly personnel and service personnel that occur due to electrical and thermal leak when accessing an active battery pack and further reduce the bulk and weight of the battery pack to enable usage of the same in compact spaces for example like an electrically powered two-wheeler.

Disclosed herein is a battery pack casing. The battery pack casing comprising a lid and a battery container to house a plurality of energy storage devices. The lid comprises a flat outer surface provided with one or more fasteners to fasten the lid to the battery container. The lid is made from a material with high thermal conductivity

BRIEF DESCRIPTION OF DRAWINGS

The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

Fig. 1 illustrates a schematic representation of the battery pack casing according to one or more embodiments of the present disclosure.

Fig. 2 illustrates a schematic representation of the cell holder according to one or more embodiments of the present disclosure.

Fig:3 illustrates a schematic representation of the battery pack container and various components thereof, according to one or more embodiments of the present disclosure.

Fig. 4 illustrates a schematic representation of the arrangement of the components in the battery pack casing according to one or more embodiments of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the assemblies, structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION

The figures and the following description relate to various embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles discussed herein. Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although, a number of methods and materials similar or equivalent to those described herein can be used in the practice of the Embodiments of the present invention will be described below in detail with reference to the accompanying figures.

Disclosed herein is a battery pack casing to enclose and protect a plurality of energy storage devices in a battery pack. The battery pack casing disclosed in here further reduces the bulk of the battery pack and aids in the operation of the battery pack in optimum temperature and environment by enabling cooling of individual tabs of the plurality of energy storage devices. The invention addressed the problems of cooling individual energy storage devices, reduction of assembly process steps, improving safety of manual assembly personnel and service personnel that occur due to electrical and thermal leak when accessing an active battery pack and further reduce the bulk and weight of the battery pack to enable usage of the same in compact spaces for example like an electrically powered two-wheeler.

The battery pack casing comprising a lid and a battery container to house a plurality of energy storage devices. The lid comprises a flat outer surface provided with one or more fasteners to fasten the lid to the battery container. The lid is made from a material with high thermal conductivity.

In an embodiment the lid of the battery pack casing comprises one or more ridge-like provisions to increase the surface area of at least the flat outer surface of the lid.

In another embodiment, the lid of the battery pack casing is made from a metal or composite material is selected from a material with thermal conductivities ranging from 200 W/mk to 450

W/mK In yet another embodiment, the battery container comprises a cell holder at a bottom surface, wherein the cell holder comprises a substrate with a plurality of cavities to house the plurality of electronic storage devices and each of the plurality of electronic storage devices comprises a tab for electrical contact, wherein the energy storage devices are placed in the cell holder in a manner such that the tabs of the plurality of energy storage devices faces away from the plurality of cavities.

In another embodiment the battery container is made of a composite material selected from ABS plastic, impact phase changing polymers, Polypropylene plastic, HDPE polymer, aramid fibres, Carbon fibre-based composites etc to absorb impact.

In an embodiment the lid is coupled to a cooling system comprises a controller and at least one electrothermal device, wherein the at least one electrothermal device is in contact with an inner side of the lid through a thermal pad and coupled to the plurality of electronic storage devices. The controller is configured to at least regulate a temperature on the lid.

In another embodiment, the cooling system further comprises, one or more peripheral devices associated with the controller to enable cooling.

In yet another embodiment the one or more peripheral device comprises one or more sensors, a fan, air blower, cooling tubes, radiators, thermocouples etc. . .

In another embodiment, the battery pack is activated to operate only upon fastening of the lid to the battery container due to the pressure exerted by the lid on the at least one electrothermal device. Figure. 1 illustrates a schematic representation of the battery pack casing according to one or more embodiments of the present disclosure. It must be understood to a person skilled in art that the present invention may also be implemented in various morphologies, other than as shown in Fig. 1.

The battery pack casing is divided into two parts, namely a lid (a) and a battery container (b) as shown in Fig 1. Each of these casings consists of the following parts/components, as explained further.

The lid (a) comprises a flat outer surface (c) provided with one or more fasteners (d) to fasten the lid (a) to the battery container (b). The flat outer surface (c), a thermally conductive metal/ composite material like aluminium alloy, copper, inorganic porous thermoplastic elastomers, silver coated aluminium alloy etc that has high thermal conducting capabilities. In another embodiment (no shown in fig), the lid (a) has small ridge-like indentations on the outside surface of the lid (a) to ensure increased surface area for cooling. The internal surface of the lid (a) in another embodiment has structural ribs in the form of cast/machined ribs that increase surface contact to the heat transfer medium which in certain case may comprise one of a thermal pad, thermal coating, inorganic substance placed between a plurality electronic storage device and the lid (a). In a non-limiting embodiment at least one electrothermal device that is thermally and electrically conductive is placed over the plurality of the electronic devices to draw heat from the same. The heat transfer medium in that case act as an insulative layer to prevent any electrical leak. This ensures heat draw away from the cells surface or tabs of the plurality of electronic storage devices. The lid (a) in accordance with an embodiment of the present invention is in constant contact with heat transfer mediums like a thermal pad or thermal layer or an inorganic substance that is highly thermally conductive, but electrically insulated in contact with the energy storage devices in the battery pack casing. This setup allows for the inner surface of the lid (a) to be in contact with the cell tabs via the thermally conductive but electrically insulated thermal pad/layer/ inorganic substance. This thermal pad transfers the heat by virtue of its ability to extract heat from the hotspot it is in contact with, into the lid (a) which behaves as a heat sink. The lid (a) behaves as a heat sink due to the temperature difference between the cavity in the battery container (b), internal components, the plurality of energy storage devices of the battery pack casing and the external atmosphere. The outer surface of the lid (a) is in contact with a cooling system thus the lid (a) behaves as a thermal heat sink in helping cool the internal cavity of the battery pack which can include a plurality of energy storage devices. The effectiveness of the heat removal in a heat sink is also a function of the thermal properties of the material used in conjunction with the air flow available over the said surface. Therefore the lid (a) behaves as good as a heat sink as the material used is a highly thermally conductive material that ensures heat extraction is as good as a conventional heat sink.

Typical battery packs dissipate heat away from the energy storage devices through convective forms of heat transfer which are not effective in removing heat away from the energy storage devices. This also adds a complexity in increasing the weight of the battery pack as there is a separate thermal extraction mechanism which adds weight to the battery packs and complexity in manufacturing.

Further, the second part of the battery pack casing comprises the batter container. The battery container (b) comprises the rugged outer periphery of the battery pack casing, also can be called as battery ‘exo-skeleton’, made up of a composite material encompassing all four sides of the periphery of a rectangle/square casing capable of impact absorption with a rectangular/square cavity within to house and make space for a component consisting of multiple circular cut- outs/cavities on the inner surface of the box, also known as a ‘Cell-Holder’.

Figure. 2 illustrates a schematic representation of the cell holder (e) according to one or more embodiments of the present disclosure.

The ‘cell holder (e)’ as shown in Fig 2 is used to accommodate a plurality of cylindrical energy storage units/cells placed in a vertical position where one of the tabs/terminals of the cells are facing towards the flat surface of the exo-skeleton of the casing shown in Fig 2. The cell holder (e) in an embodiment is made from a flame-retardant material to prevent propagation of any thermal runaway internally amongst the plurality of energy storage devices placed in the cell holder (e). The battery pack consists of a plurality of energy storage devices as shown in Figure 3 is arranged vertically in a housing called the 'cell holder (e)' 2, which has multiple cavities and divided into two parts, namely the bottom half and the top half. The cavities present in these cell holders (e) are the size of the outer diameter of the individual energy storage devices used in the application of energy storage devices.

There is a cell holder (e) at the bottom (2) of the battery pack, shown in figure 3 and 4 with a plurality of cavities holding a plurality of energy storage devices, fit into the cavities.

The ‘cell-holder’ (shown in Fig 2) mentioned above is made up of flame-retardant composite material, which prevent the whole pack from catching fire if and when a single or multiple cell(s) has reached a state of thermal runaway, thus restricting the resulting fire to those particular cell(s) and safeguarding the other cells from flame propagation throughout the pack.

This ensures safe service-ability of the pack via replacement of those particular affected cells, rather than replacement of the whole pack. The cell-holder also mentioned above has a ‘honeycomb’ (shown in Fig 2) like geometry designed into it which makes it is highly structurally rigid reducing the impact to the cell in case of an accident/impact on the whole battery pack.

Figure:3 illustrates a schematic representation of the battery pack container and various components thereof according to one or more embodiments of the present disclosure.

In one embodiment of a top cell holder (1) shown in figure 3 consists of at least one electro thermal device 5, that is assembled on top of the said cell holder. In an embodiment, the at least one electrothermal device is a busbar with a plurality of flat projections (6). In another embodiment the at least one electrothermal device is a composite printed circuit board (CPCB).

In another embodiment, the at least one electrothermal device consists of metal conducting layers connecting the energy devices tab's, which are assembled on top of the said top and bottom cell holders (1, 2) wherein the metal conducting layer has an arrangement shown in figure 3. The metal conducting layer has projections (6) of an electrically conductive metal (6) towards the energy storage devices tabs/electrode, that has a flat surface on its edge periphery's. This flat projection acts as a pressure contact towards the energy devices' electrodes/tabs. This at least one electrothermal device is not only electrically conductive, but also thermally conductive, and transfers heat from the tabs/terminals of the cells to a thermally conductive but electrically insulative ‘thermal pad (4)’. Further an insulative layer is sandwiched in between the current carrying conductor layer and the flat outer surface (c), made up of metal/composite heat sink outer surface of the battery casing that acts as heat sink when in contact with the outer atmosphere.

Therefore, the battery pack casing in an embodiment may consist of the assembly using a plurality of cell holders, at least one of electrothermal devices (4) and a heat transfer medium (4) over a plurality of energy storage devices in a particular series and parallel connection to produce the desired voltage and capacity, which when electro-mechanically connected to each other with the cells, will provide us with required voltage and capacity of the pack.

The above components are assembled into a battery casing in such a way as shown in Figure 3 and 4, that they are vertically stacked upon each other to create a ‘ Sandwich’ . A pressure is created by the lid (a) onto this sandwich assembly, the thermal pad (4), the at least one electrothermal device when fastening the lid (a) to the battery container (b) and the assembly of a components are forced to be in surface contact at all times, which ensures constant and consistent contact throughout the whole current carrying conductor. This results in the plurality of the energy storage devices being ‘tab cooled’. This reduces the risk of human electrocution/shock while manufacturing or assembling the pack as the pack would not be active/live until the top and bottom casings are fastened to each other, thus effectively ensuring safety of the user/personnel working on the pack.

Cooling System:

In a non-limiting embodiment, the lid (a) in the battery pack is coupled to a cooling system. The coupling may comprise one or more of a physical coupling, a thermal coupling or an electrical coupling with one or more components of the cooling system comprising a controller, an at least one electrothermal devices (4) and one or more peripheral devices associated with the controller to enable cooling, the at least one electrothermal device consists of metal conducting layers connecting the energy devices tab's, which are assembled on top of the said top and bottom cell holders (1,2) wherein the metal conducting layer has an arrangement shown in figure 3. The at least one electrothermal device is in contact with an inner side of the lid (a) through a thermal pad (4) and coupled to the plurality of electronic storage devices (3). The metal conducting layer of the at least one electrothermal device in an embodiment has projections (6) of an electrically conductive metal towards the energy storage devices tabs/electrode, that has a flat surface on its edge periphery's. This flat projection acts as a pressure contact towards the energy devices' electrodes/tabs. This at least one electrothermal device is not only electrically conductive, but also thermally conductive, and transfers heat from the tabs/terminals of the cells to a thermally conductive but electrically insulative ‘ thermal pad (4)’.

Further, the controller of the cooling system is configured to at least regulate a temperature on the lid (a) through the one or more peripheral device associated with the system comprising at least one of a one or more sensors, a fan, an air blower, cooling tubes, radiators, thermocouples, pettier units etc. The cooling system allows for heat transfer due to virtue of temperature difference, therefore in an embodiment, the one or more sensors may comprise at least a temperature sensor, humidity sensor, current sensor etc. In an embodiment, the air on the outer surface of the lid (a) is cooled due to flow of cooler atmospheric air via passive flow of air or through forced air flow via fans/ external pressurised air flow devices.

In other words, the cooling system coupled to the lid (a) is configured to cool the lid (a) of the battery pack casing in order to tab cool the plurality of energy storage devices. The cooling system including the battery pack with the battery casing also comprise various aspects in the assembly of the battery pack casing to enable an efficient cooling for improving the operational life of the battery pack by better extraction of heat from each of the plurality of energy storage device tabs.

Firstly, the battery pack lid (a) comprises an inner surface with ribs in some embodiments. In an embodiment the structured ribs on the inner surface of the lid (a) behave as contact pressure points to connect the interconnect mechanism as well as the thermal contact points that ensure heat is drawn from the cells to the heat sink/lid (a) of the pack The lid (a) that is made of metal/composite material with high thermal conductivity acts as a heat sink in conducting just the heat from the plurality of energy storage devices to the outer surface. In an embodiment, a selected metal or composite material for a lid may comprise thermal conductivity ranging from 200 W/mk to 450 W/mK. This setup of the lid (a) not only allows for thermal extraction, but also exerts pressure/force onto the energy storage systems’ tab’s which ensures contact of these cells onto the interconnect mechanism. This ensures that the complexity of a welding technique is not required, further reducing the cost, weight and complexity of manufacturing a battery pack. The lid (a) behaves as an electrical insulator mechanism for service personnel as once the force/pressure exerted by the lid (a) onto the battery pack is removed by unfastening mechanisms, the battery pack’s electrical connections are no longer completing the electric circuitry thanks to the pressure contact interconnect mechanism in the battery pack. This allows for individual cell level serviceability and also the ability to remove/replace individual or plurality of cells accordingly in the field as well. This reduces the safety risk involved in repairing or replacing energy storage devices. The outer environment around the battery pack casing is maintained at a cooler temperature to draw the heat out of the battery pack. A temperature sensor in an embodiment may be used to further ensure that maintenance of optimum temperature of the lid (a) to prevent any accidental over-heating.

Further the at least one electrothermal devices (4) in contact with an inner side of the lid (a) through a thermal pad (4) and coupled to the plurality of electronic storage devices (3). The at least one electrothermal devices (4) may comprise projections (6) of an electrically conductive metal directed towards the energy storage devices tabs/electrode, that has a flat surface on its edge periphery's. This flat projection acts as a pressure contact towards the energy devices' electrodes/tabs. When the at least one electrothermal device is placed over the plurality of electronic storage devices (3), a heat transfer medium (4) is further placed over the at least one electrothermal device to conduct heat away from the individual tabs of the plurality of electronic storage devices (3) and prevent any electrical leakage. Therefore, when the lid (a) is fastened over the battery container (b), the ribs in the inner side of the lid (a) may exert pressure on the at least one electrothermal devices (4) to make proper contact with the tabs and extract the heat efficiently, thereby ensuring the optimum operation of the battery pack through out its life cycle. Further the use of fasteners (d) instead of welding enables easy serviceability and replacement of only the cells that requires replacement. Further, as the cell holder is made from a flame-retardant material it also prevents thermal runaways even in case of one or more failed electronic storage devices (3) of the plurality of electronic storage devices (3). Therefore, the battery pack casing and the cooling system as a whole addresses all the problems mentioned above comprising cooling individual energy storage devices, reduction of assembly process steps, improving safety of manual assembly personnel and service personnel that occur due to electrical and thermal leak when accessing an active battery pack and further reduce the bulk and weight of the battery pack to enable usage of the same in compact spaces for example like a electrically powered two-wheeler.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the 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 will so fully reveal 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, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications 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 modifications in the nature of the disclosure or the preferred embodiments 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.