DESC:“A BATTERY PACK AND A METHOD OF THERMAL MANAGEMENT IN A BATTERY PACK”

FIELD OF THE INVENTION
The present disclosure relates toa battery pack, and more particularly to a battery pack and a method of thermal management in a battery pack. The present application is based on, and claims priority from an Indian Provisional Application Number: 202341024724 filed on 31-03-2023, the disclosure of which is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION
In general, a cell is a device that stores chemical energy and converts the chemical energy into electrical energy. The chemical reactions in the cell involve the flow of electrons between an anode and a cathode, through an external circuit, so that a temperature level of the cells may increase, which increases the temperature level of the battery pack.An atmospheric temperature is also the reason for the temperature hike in the battery pack. The performance of the battery pack/cell is affected heavily by temperature variations.In some cases, the increased temperature levels may lead to a fire accident and thermal runaway in the worst cases. So, it is very important to monitor and control the temperature level of the battery pack. Maintaining the temperature level of the battery pack with optimal temperature is a difficult task.
In a conventional method, many electric vehicle manufacturers come up with a coolant method and a heat sink method which reduces the temperature level of the cell and the battery pack, but this method is not efficient. At the same time, the coolant method and the heat sink method make the battery pack big, complex, and expensive. In a recent method, most vehicle manufacturers use thermal conductive materials to reduce the temperature level of the cells and the battery pack. However, the thermally conductive materials dissipate heat on a radial surface of the cells due to their dispensing position, but there is no option to dissipate heat generated at the axial surface of the cells.
In general, the heat energy produced in the cell is symmetric but the high thermal conductivity is in the axial surface of the cells so that the heat dissipation is more on the axial surface compared to the radial surface. In addition to that, most vehicle manufacturers use a phase change material (PCM) in the battery pack to control heat. As used herein, the phase change material (PCM) is a substance that releases/absorbs sufficient energy at phase transition to provide useful heat or cooling. Generally, the transition will be from one of the first two fundamental states of matter - solid and liquid - to the other. The PCM absorbs the heat from the cells to cool the cells. Due to the absorption process, the state of the PCM changed into a liquid state from a solid state.
In general, the atoms in the liquids were loosely bonded. Thus, the liquids containing atoms arranged loosely lead to the occupancy of higher volume compared to solids. So, the PCM (liquid state) occupies a higher volume than the solid PCM (solid state) in the battery pack. The volumetric expansion in the PCM may increase thermal pressure and release one or more gases. An increased thermal pressure and one or more gases may affect the battery pack. The conventional method does not have any course of action to solve it. So, the conventional and the recent methods are not efficient to solve the above-mentioned issues of the battery pack.
Hence, there remains a need for an improved approach to provide a battery pack with thermal management to address the aforementioned issues.

SUMMARY OF THE INVENTION
Accordingly, the embodiments herein disclose a battery pack. The battery pack includes a first thermally conductive layer is configured to spread across the battery pack and maintain an equal space between a plurality of cells, wherein the first thermally conductive layer is filled to a predetermined height in a bottom battery casing, wherein the first thermally conductive layer is facing an axial surface and a circumferential surface of the plurality of cells to absorb heat from the plurality of cells and transfer the heat to a plurality of fins. A second thermally conductive layer is configured to spread across the battery pack and maintain an equal space between the plurality of cells, wherein the second thermally conductive layer is facing the circumferential surface of the plurality of cells to absorb the heat from the plurality of cells, wherein the second thermally conductive layer is positioned on a top portion of the first thermally conductive layer. A thermally insulative layer is configured to prevent thermal runaway and reduce shock and vibration, wherein the thermally insulative layer is filled on a top portion of a second cell holder, wherein the thermally insulative layer is configured to suppress fire during the thermal runaway of the plurality of cells.
The battery pack further includes a first cell holder that comprises a plurality of cavities and is configured to hold the plurality of cells in a predetermined position, wherein the first cell holder is configured to provide an equal space between the bottom battery casing and a bottom surface of the plurality of cells.The second cell holder is positioned between the first cell holder and a third cell holder by sliding through, and tight fit to the plurality of cells to maintain a predetermined gap between the second cell holder and the second thermally conductive layer, wherein the second cell holder is configured to provide an equal space between the plurality of cells. A plurality of cell holder sleeves is configured to support and hold at least one of the first cell holder, the second cell holder, and the third cell holder along with the plurality of cells. The third cell holder is placed above the thermally insulative layer and is configured to provide an equal space between the pluralities of cells.
In some embodiments, the first thermally conductive layer includes a resin, a polymeric/non-polymeric material, a poly urethane, an epoxy, a dielectric, a solid PCM, and a silicon.
In some embodiments, the second thermallyconductive layer includes a phase change material (PCM), wherein the phase change material comprises organic phase change materials or inorganic phase change materials.
In some embodiments, the thermally insulative layer includes a silicon foam, a foam, a polyurethane foam, a polyurethane, a polystyrene, a silicon, and a polyisocyanurate.
In some embodiments, the battery pack further comprises an interconnector, wherein the interconnector is configured to connect different polarities of the plurality of cells by using a plurality of connectors and is positioned on a top portion of the third cell holder, and the plurality of cells.
In some embodiments, the predetermined gap is filled with one or more gases to maintain thermal and chemical stability of the battery pack.
In another aspect, the method of thermal management in a battery pack includes (a) filling a first thermally conductive layer to a predetermined height of a bottom battery casing; (b) dipping, a first cell holder and a plurality of cells into the bottom battery casing of the battery packusing a jig; (c) filing a second thermally conductive layer on a top of the first thermally conductive layer; (d) positioning a second cell holder between the first cell holder and the third cell holder by sliding through, and tight fit to the plurality of cells to maintain a predetermined gap between the second cell holder and the second thermally conductive layer; (e) filing a thermally insulative layer above the second cell holder; (f) placing the third cell holder on top of the thermally insulative layer; (g)connecting different polarities of the plurality of cells using a plurality of connectorsby an interconnector;(h) stacking a thermal interface material on a top portion of the plurality of connectors; (i) receiving heat generated from the battery pack through the conduction processby the thermal interface material; and (j) transferring, the thermal interface material, and the heat generated from the battery pack to a top battery casing.
In yet another aspect of the method further includes the steps of (1) placing the first cell holder, and the plurality of cells into the bottom battery casing of the battery pack; (2) pouring the first thermally conductive layer to the predetermined height of the bottom battery casing of the battery pack; (3) filing a second thermally conductive layer on a top of the first thermally conductive layer; (4) positioning a second cell holder between the first cell holder and the third cell holder by sliding through, and tight fit to the plurality of cells to maintain a predetermined gap between the second cell holder and the second thermally conductive layer;(5) filing a thermally insulative layer above the second cell holder; (6) placing the third cell holder (120) on top of the thermally insulative layer; (7) connectingdifferent polarities of the plurality of cells using a plurality of connectorsby an interconnector; (8) stacking a thermal interface material on a top portion of the plurality of connectors; (9) receiving, by the thermal interface material, heat generated from the battery pack through the conduction process; and (10) transferring, the thermal interface material, and the heat generated from the battery pack to a top battery casing.
In some embodiments, the first thermally conductive layer includes a resin, a polymeric/non-polymeric material, a polyurethane, an epoxy, a dielectric, a solid PCM, and a silicon.
In some embodiments, the second thermally conductive layer includes a phase change material (PCM). The phase change material includes organic phase change materials or inorganic phase change materials.
In some embodiments, the thermally insulative layer includes a silicon foam, a foam, a polyurethane foam, a polyurethane, a polystyrene, a silicon, and a polyisocyanurate.
In some embodiments, the method further including the steps of :providing the predetermined gap for filling one or more gases to maintain thermal and chemical stability of the battery pack.
Accordingly, the embodiments herein disclose a method of thermal management in a battery pack. The method includes the following steps: (a) filling a first thermally conductive layer to a predetermined height of a bottom battery casing; (b) dipping a first cell holder, and a plurality of cells into the bottom battery casing of the battery pack by using a jig; (c) filling a second thermally conductive layer on a top portion of the first thermally conductive layer; (d) positioning a second cell holder between the first cell holder and a third cell holder by sliding through, and tight fit to the plurality of cells to maintain a predetermined gap between the second cell holder and the second thermally conductive layer; (e) filling a thermally insulative layer above the second cell holder; (f) placing the third cell holder on a top portion of the thermally insulative layer; (g) connecting different polarities of the plurality of cells using a plurality of connectors by an interconnector; (h) stacking a thermal interface material on a top portion of the plurality of connectors; (i) receiving heat generated from the battery pack through the conduction process by the thermal interface material; and (j) transferring, the heat generated from the battery pack to a top battery casing by the thermal interface material.
In one embodiment, the method further includes the first cell holder, and the plurality of cells are placed into the bottom battery casing of the battery pack.The first thermally conductive layer is poured to the predetermined height of the bottom battery casing of the battery pack.
In another embodiment, the method further includesthe predetermined gap provided for filling one or more gases to maintain the thermal and chemical stability of the battery pack.
In a conventional approach, embodiments herein disclose a method of thermal management in a battery pack. The method includes the following steps: (a) placing the first cell holder, and the plurality of cells into the bottom battery casing of the battery pack; (b) pouring the first thermally conductive layer to the predetermined height of the bottom battery casing of the battery pack; (c) filing a second thermally conductive layer on a top of the first thermally conductive layer; (d) positioning a second cell holder between the first cell holder and the third cell holder by sliding through, and tight fit to the plurality of cells to maintain a predetermined gap between the second cell holder and the second thermally conductive layer; (e) filing a thermally insulative layer above the second cell holder; (f) placing the third cell holder on top of the thermally insulative layer; (g) connecting, by an interconnector, different polarities of the plurality of cells using a plurality of connectors; (h) stacking a thermal interface material on a top portion of the plurality of connectors; (i) receiving, by the thermal interface material, heat generated from the battery pack through the conduction process; and (j) transferring, the thermal interface material, and the heat generated from the battery pack to a top battery casing.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the invention thereof, and the embodiments herein include all such modifications.

DESCRIPTION OF THE DRAWINGS
This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
FIG. 1 illustrates an exploded perspective view of a battery pack according to an embodiment as disclosed herein;
FIG. 2 illustrates a cross-sectional view of the battery pack, according to the embodiment as disclosed herein; and
FIG. 3A&3B illustrate a flow diagram of a method of thermal management of the battery pack, according to the embodiment as disclosed herein.

DESCRIPTION OF THE INVENTION
In the following description, for the purposes of explanation, various specific details are set forth in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein.
The ensuing description provides exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.
The word “exemplary” and/or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive—in a manner similar to the term “comprising” as an open transition word—without precluding any additional or other elements.
Reference throughout this specification to “one embodiment” or “an embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
Accordingly, the embodiments herein disclose a battery pack. The battery pack includes a first thermally conductive layer is configured to spread across the battery pack and maintain an equal space between a plurality of cells, wherein the first thermally conductive layer is filled to a predetermined height in a bottom battery casing, wherein the first thermally conductive layer is facing an axial surface and a circumferential surface of the plurality of cells to absorb heat from the plurality of cells and transfer the heat to a plurality of fins. A second thermally conductive layer is configured to spread across the battery pack and maintain an equal space between the plurality of cells, wherein the second thermally conductive layer is facing the circumferential surface of the plurality of cells to absorb the heat from the plurality of cells, wherein the second thermally conductive layer is positioned on a top portion of the first thermally conductive layer. A thermally insulative layer is configured to prevent thermal runaway and reduce shock and vibration, wherein the thermally insulative layer is filled on a top portion of a second cell holder, wherein the thermally insulative layer is configured to suppress fire during the thermal runaway of the plurality of cells.
The battery pack further includes a first cell holder that comprises a plurality of cavities and is configured to hold the plurality of cells in a predetermined position, wherein the first cell holder is configured to provide an equal space between the bottom battery casing and a bottom surface of the plurality of cells.The second cell holder is positioned between the first cell holder and a third cell holder by sliding through, and tight fit to the plurality of cells to maintain a predetermined gap between the second cell holder and the second thermally conductive layer, wherein the second cell holder is configured to provide an equal space between the plurality of cells. A plurality of cell holder sleeves is configured to support and hold at least one of the first cell holder, the second cell holder, and the third cell holder along with the plurality of cells. The third cell holder is placed above the thermally insulative layer and is configured to provide an equal space between the plurality of cells.
Referring now to the drawings and more particularly to FIGS. 1 to3, where similar reference characters denote corresponding features consistently throughout the figure, these are shown as preferred embodiments.
FIG. 1 illustrates anexploded perspective view of a battery pack 100, according to an embodiment as disclosed herein. The battery pack 100 includes a bottom battery casing 102, a plurality of connectors (not shown in the figure), an interconnector 106, a thermal interface material 108, a top battery casing 110, a first cell holder 112, a plurality of cells 114, a second cell holder 116, a plurality of cell holder sleeves 118, a third cell holder 120 and a plurality of fins 122. The battery pack 100 further includes a first thermally conductive layer 124, a second thermally conductive layer 126, and a thermally insulative layer 128. In one embodiment, the thermal interface material 108 may include, but not limited to, a thermal pad, a thermal paste, a silicon pad, a gap pad, a thermal grease, a thermal gap filler, and the like. In one embodiment, the interconnector 106 may include, but not limited to, a PCB (Printed Circuit Board), a current collector, and the like.
The battery pack 100 further includes the first thermally conductive layer 124, the second thermally conductive layer 126, and the thermally insulative layer 128. In an embodiment, the first thermally conductive layer 124 may include, but not limited to, a resin, a polymeric/non-polymeric material, a polyurethane, an epoxy, a dielectric, a solid PCM, and a silicon. The first thermally conductive layer 124 is configured to spread across the battery pack 100 and maintainequal space between the plurality of cells 114. The first thermally conductive layer 124 is filled to a predetermined height in the bottom battery casing 102. The first thermally conductive layer 124 faces axial surface and circumferential surface of the plurality of cells 114 to absorb heat from the plurality of cells 114 and transfer the heat to the plurality of fins 122. The first thermally conductive layer 124 may provide better structural stability, and better structural rigidity to the battery pack 100. In one embodiment, the first thermally conductive layer 124 retains the position of the plurality of cells 114. In another embodiment, the first thermally conductive layer 124 increases the durability of the plurality of cells 114. Furthermore, the first thermally conductive layer 124 provides electrical insulation between the plurality of cells 114, and the bottom battery casing 102.
The first thermally conductive layer 124 further provides increased durability to the battery pack 100.The first thermally conductive layer 124 transfers the heat from the plurality of cells 114 to the plurality of fins 122 through the conduction process.The first thermally conductive layer 124 further resists movements of the plurality of the cells 114 in the battery pack 100.
The first thermally conductive layer 124 is configured to reduce the heat of the plurality of cells 114 by transferring the heat to the plurality of fins 122. As used herein, the fin is defined as a surface that extends from an object to increase the rate of heat transfer to or from the environment by increasing convection. The plurality of fins 122 is positioned on the outer walls of the top battery casing 110, and the bottom battery casing 102.
The second thermally conductive layer 126is configured to spread across the battery pack 100and maintains an equal space between the plurality of cells 114. The second thermallyconductive layer 126 facesa circumferential surface of the plurality of cells 114 to absorb the heat from the plurality of cells 114.The second thermallyconductive layer 126is positioned on a top portion of the first thermallyconductive layer 124.
The second thermally conductive layer 126 may include a phase change material (PCM). As used here in, the phase change material is defined as a substance that releases/absorbs sufficient energy at phase transition to provide useful heat or cooling. Generally, the transition will be from one of the first two fundamental states of matter - solid and liquid - to the other. In one embodiment, the phase change material may include, but not limited to, organic phase change materials or inorganic phase change materials. The second thermally conductive layer 126 absorbs the heat from the plurality of cells 114.
The thermally isolative layer 128 is configured to prevent thermal runaway and reduce shock and vibration. The thermally insulative layer 128is filled on a top portion of the second cell holder 116. The thermally in sulative layer 128is configured to suppress fire during the thermal runaway of the plurality of cells 114.
The thermally isolative layer 128 may include, but not limited to a thermal runaway mitigation material. In one embodiment, the thermally insulative layer 128 prevents thermal runaway propagation. In one embodiment, the thermal runaway mitigation material may include, but not limited to, a silicon foam, a foam, a polyurethane foam, a polyurethane, a polystyrene, a silicon, and a polyisocyanurate. The thermally insulative layer 128 may include, but not limited to, a low-density thermal conductive material, and an electrically insulating material. The thermally insulative layer 128 is configured to reduce shock and vibration.The thermally insulative layer 128 may include a flame-retardant capacity.
The bottom battery casing 102 is filled with the first thermally conductive layer 124 to the predetermined height.The predetermined height depends on the heat generated by the plurality of cells 114, or the battery pack 100. The first thermally conductive layer 124 is poured to the predetermined height of the bottom battery casing 102 of the battery pack 100, then the first cell holder 112, and the plurality of cells 114 dipped into the bottom battery casing 102 of the battery pack 100. The first cell holder 112, and the plurality of cells 114 dipped into the bottom battery casing 102 of the battery pack 100 in such a way that the first thermally conductive layer 124 is facing the axial surface of the plurality of cells 114. In one embodiment, the first cell holder 112, and the plurality of cells 114 dipped into the bottom battery casing 102 of the battery pack 100 using a jig.
In one embodiment, the first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 then the first thermally conductive layer 124 is poured to the predetermined height of the bottom battery casing 102 of the battery pack 100. The first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 in such a way that the first thermally conductive layer 124 is facing the axial surface of the plurality of cells 114. In another embodiment, the first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 using the jig.
The first thermally conductive layer 124 spreads across the battery pack 100 and maintains the equal space between the plurality of cells 114 and the bottom battery casing 102. The first thermally conductive layer 124 is configured to reduce shock and vibration.
The first cell holder 112 includes a plurality of cavities and is configured to hold the plurality of cells 114in a predetermined position.The first cell holder 112 is configured to provide an equal space between the bottom battery casing 102 and the bottom surface of the plurality of cells 114.
The first cell holder 112 is positioned between the bottom battery casing 102 and the plurality of cells 114. In one embodiment, the first cell holder 112 may include, but not limited to, thermally conductive and electrically insulative material. In another embodiment, the first cell holder 112 may include, but not limited to, a synthetic polymer-based material, a non-synthetic polymer-based material, and a thermoset plastic material. In one embodiment, the plurality of cells 114 may include, but not limited to, nickel cadmium, alkaline, nickel metal hydride (NIMH), lithium-ion, lithium iron phosphate or LFP, nickel hydrogen, nickel-zinc, electro-chemical cells, sodium ion, and the like.The plurality of cells 114 are connected with the interconnector 106 to configure one or more connections between the plurality of cells 114 are a series connection, a parallel connection, and a combination of a series and a parallel connection and the like.
Further, the first cell holder 112 is configured to provide the equal space between the bottom battery casing 102 and the bottom surface of the plurality of cells 114.In one embodiment,the predetermined space between the bottom battery casing 102 and the bottom surface of the plurality of cells 114 may depend, but not limited to, thermal behavior, structural stability, and electrical insulation of the plurality of cells 114. In addition to that, the predetermined space provides insulation by the first thermally conductive layer 124. Further, the first cell holder 112 is configured to increase the structural rigidity of the batter pack 100.
Once the first cell holder 112, and the plurality of cells 114 are dipped/placed in the bottom battery casing 102, the second thermally conductive layer 126 is dispensed above the first thermally conductive layer 124. The second thermally conductive layer 126 is configured to reduce the heat of the plurality of cells 114. In one embodiment, the second thermally conductive layer 126 is dispensed (as a liquid) in such a way that the second thermally conductive layer 126 is facing the radial surface of the plurality of cells 114. The second thermally conductive layer 126 spreads across the battery pack 100 and provides a predetermined space between the plurality of cells 114.
The plurality of cell holder sleeves 118 is configured to support and hold the first cell holder 112, the second cell holder 116,and the third cell holder 120 along with the plurality of cells 114. In one embodiment, the plurality of cell holder sleeves 118 may be projected upwards from the first cell holder 112 and connected to the second cell holder 116 and the third cell holder 120. In another embodiment, the plurality of cell holder sleeves 118 may include, but not limited to, a plurality of cell holder spacers, and a plurality of cell holder supporters. In yet another embodiment, the plurality of cell holder sleeves 118 may be projected downwards from the second cell holder 116 and the third cell holder 120 and connected to the first cell holder 112. In yet another embodiment, the plurality of cell holder sleeves 118 may be projected (i) upward from the first cell holder 112, and (ii) downward from the second cell holder 116 and the third cell holder 120 and connected with each other.
The second cell holder 116 is positioned between the first cell holder 112 and the third cell holder 120 by sliding through, and tight fit to the plurality of cells 114 to maintain a predetermined gap between the second cell holder 116 and the second thermallyconductive layer 126.The second cell holder 116 is configured to provide an equal space between the plurality of cells 114. In one embodiment, the predetermined gap is filled with one or more gases to maintain the thermal and chemical stability of the battery pack 100.
In one embodiment, the second cell holder 116 may include, but not limited to, a thermally conductive material and an electrically insulative material.In another embodiment, the second cell holder 116 may include, but not limited to, a synthetic polymer-based material, a non-synthetic polymer-based material, and a thermoset plastic material. Further, the second cell holder 116 is configured to provide the equal space between the plurality of cells 114. In one embodiment, the second cell holder 116 is configured to provide structural rigidity to the battery pack 100. In another embodiment, the second cell holder 116 is configured to reduce shock and vibration.
The battery pack 100 is provided with the predetermined gap between the second cell holder 116 and the second thermally conductive layer 126. Due to the phase change process of the second thermally conductive layer 126, the state of the second thermally conductive layer 126 is changed from a solid state to a liquid state by absorbing the heat from the plurality of cells 114 and the battery pack 100. The predetermined gap is configured to provide the space for volumetric expansion of the second thermally conductive layer 126, and one or more gases are generated at the time of the phase change process.The predetermined gap is configured to reduce the thermal pressure of the battery pack 100 by providing the space for volumetric expansion of the second thermally conductive layer 126, and the one or more gases generated at the time of the phase change process.
The third cell holder 120 is positioned above the thermally insulative layer 128 and is configured to provide an equal space between the plurality of cells 114. In one embodiment, the third cell holder 120 may include, but not limited to, a thermally conductive material and an electrically insulative material. In another embodiment, the third cell holder 120 may include, but not limited to, a synthetic polymer-based material, a non-synthetic polymer-based material, and a thermoset plastic material. Further, the third cell holder 120 is configured to provide the equal space between the plurality of cells 114. In one embodiment, the third cell holder 120 is configured to provide structural rigidity to the battery pack 100. In another embodiment, the third cell holder 120 is configured to reduce shock and vibration.
The interconnector 106 is positioned on a top portion of the third cell holder 120, and the plurality of cells 114. The interconnector 106 is configured to connect different polarities of the plurality of cells 114 by using the plurality of connectors. The interconnector 106 may include, but not limited to a PCB (Printed Circuit Board) and a current collector.In one embodiment, the plurality of connectors may be feeders. In another embodiment, the plurality of connectors may include, but not limited to, one or more current conducting elements. In yet another embodiment, the plurality of connectors may include, but not limited to, a nickel strip.
In yet another embodiment, the thermal interface material 108 may be dispensed above the plurality of connectors. The thermal interface material 108 stacks above the plurality of connectors. In one embodiment, the thermal interface material 108 may include, but not limited to, a thermal pad, a thermal paste, a silicon pad, a gap pad, a thermal grease, a thermal gap filler, and the like. In one embodiment, the thermal interface material 108 applies above the plurality of connectors. In another embodiment, the thermal interface material 108 pastes above the plurality of connectors.In yet another embodiment, the thermal interface material 108 dispenses above the plurality of connectors.
The thermal interface material 108 is configured to receive heat generated from the battery pack 100 through the conduction process.In one embodiment, the thermal interface material 108 is configured to receive the heat generated from terminals of the plurality of cells 114 through the conduction process. The thermal interface material 108 is configured to transfer the heat to the top battery casing 110. The thermal interface material 108 is compressed by the top battery casing 110 to transfer the heat which is generated from the plurality of cells 114, and the interconnector 106. The top battery casing 110 is configured to close the battery pack 100 from the top.
Furthermore, the width of the first thermally conductive layer 124, the width of the second thermally conductive layer 126, and the width of the thermally insulative layer 128 may vary based on the number of the plurality of the cells 114 present inside the battery pack 100.
FIG. 2 illustrates a cross-sectional view of the battery pack 100, according to the embodiment as disclosed herein.The battery pack 100 includes the bottom battery casing 102, the plurality of connectors, the interconnector 106, the thermal interface material 108, the top battery casing 110, the first cell holder 112, the plurality of cells 114, the second cell holder 116, the plurality of cell holder sleeves 118, and the third cell holder 120. In one embodiment, the thermal interface material 108 may include, but not limited to, a thermal pad, a thermal paste, a silicon pad, a gap pad, a thermal grease, a thermal gap filler, and the like.In one embodiment, the plurality of cell holder sleeves 118 may include, but not limited to, a plurality of cell holder spacers, and a plurality of cell holder supporters.
The first thermally conductive layer 124 is filled to the predetermined height in the bottom battery casing 102. In one embodiment, the predetermined height depends on the heat generated by the plurality of cells 114, or the battery pack 100. The first thermally conductive layer 124 is poured to the predetermined height of the bottom battery casing 102 of the battery pack 100, then the first cell holder 112, and the plurality of cells 114 dipped. The first cell holder 112, and the plurality of cells 114 dipped in such a way that the first thermally conductive layer 124 facing the axial surface and the circumferential surface of the plurality of cells 114 to absorb the heat from the plurality of cells 114 and transfer the heat to the plurality of fins 122. The first cell holder 112, and the plurality of cells 114 dipped into the bottom battery casing 102 of the battery pack 100 using a jig.
In another embodiment, the first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 then the first thermally conductive layer 124 is poured to the predetermined height of the bottom battery casing 102 of the battery pack 100. The first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 in such a way that the first thermally conductive layer 124 is facing the axial surface and the circumferential surface of the plurality of cells 114 to absorb the heat from the plurality of cells 114 and transfer the heat to the plurality of fins 122. The first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 using the jig.
The first thermally conductive layer 124 spreads across the battery pack 100 and maintains the equal space between the plurality of cells 114 and the bottom battery casing 102. The first thermally conductive layer 124 is configured to reduce shock and vibration.
The second thermally conductive layer 126 is filled above the first thermally conductive layer 124. In addition to that, the battery pack 100 provides the predetermined gap between the second cell holder 116 and the second thermally conductive layer 126. Due to the phase change process of the second thermally conductive layer 126, the state of the second thermally conductive layer 126 is changed from the solid state to the liquid state by absorbing the heat from the plurality of cells 114 and the battery pack 100. The predetermined gap is configured to provide space for volumetric expansion of the second thermally conductive layer 126, and the one or more gases are generated at the time of the phase change process. The predetermined gap is configured to reduce the thermal pressure of the battery pack 100 by providing the space for volumetric expansion of the second thermally conductive layer 126, and the one or more gases generated at the time of the phase change process.
In one embodiment, the battery pack 100 is designed in such a way the predetermined gap will be positioned between the second cell holder 116 and the second thermally conductive layer 126. Furthermore, the predetermined gap is filled by the second thermally conductive layer 126 when the second thermally conductive layer 126 is changed to the liquid state by absorbing the heat from the plurality of cells 114, and the battery pack 100. The predetermined gap is positioned on the top of the second thermally conductive layer 126.Then the thermally insulative layer 128 is dispensed on the top of the second cell holder 116.
The third cell holder 120 is positioned on top of the thermally insulative layer 128. In one embodiment, the third cell holder 120 may include, but not limited to, a thermally conductive material and an electrically insulative material. In another embodiment, the third cell holder 120 may include, but not limited to, a synthetic polymer-based material, a non-synthetic polymer-based material, and a thermoset plastic material. Further, the third cell holder 120 is configured to provide the equal space between the plurality of cells 114. In one embodiment, the third cell holder 120 is configured to provide structural rigidity to the battery pack 100. In another embodiment, the third cell holder 120 is configured to reduce shock and vibration.
The interconnector 106 is positioned on top of the third cell holder 120, and the plurality of cells 114.Furthermore, the interconnector 106 is configured to connect different polarities of the plurality of cells 114 by using the plurality of connectors. In one embodiment, the plurality of connectorsmay be feeders. In another embodiment, the plurality of connectors may include, but not limited to, one or more current conducting elements. In yet another embodiment, the plurality of connectors may include, but not limited to, a nickel strip. In addition to that, the thermal interface material 108 is poisoned on the top of the interconnector 106.Further, the thermal interface material 108 may include, but not limited to, an electrically insulative material.
The thermal interface material 108 stacks above the plurality of connectors. In one embodiment, the thermal interface material 108 may include, but not limited to, a thermal pad, a thermal paste, a silicon pad, a gap pad, a thermal grease, a thermal gap filler, and the like. In one embodiment, the thermal interface material 108 applies above the plurality of connectors. In another embodiment, the thermal interface material 108 pastes above the plurality of connectors. In yet another embodiment, the thermal interface material 108 dispenses above the plurality of connectors.
The thermal interface material 108 is configured to receive the heat generated from the battery pack 100 through the conduction process.In one embodiment, the thermal interface material 108 is configured to receive the heat that is generated from the terminals of the plurality of cells 114. The thermal interface material 108 is configured to transfer the heat to the top battery casing 110.The thermal interface material 108 and the top battery casing 110 are connected together. The top battery casing 110 is configured to close the battery pack 100.
FIG. 3A&3B illustrates a flow diagram of a method 300 of thermal management of the battery pack 100, according to the embodiment as disclosed herein.At step 302, filling a first thermally conductive layer 124 to a predetermined height of a bottom battery casing 102. In one embodiment, the first thermally conductive layer 124 may include, but not limited to, a resin, a polymeric/non-polymeric material, a polyurethane, an epoxy, a dielectric, a solid PCM,and a silicon.The first thermally conductive layer 124 is facing an axial surface and a circumferential surface of the plurality of cells 114 to absorb heat from the plurality of cells 114 and transfer the heat to a plurality of fins 122. The first thermally conductive layer 124 may provide better structural stability, and better structural rigidity to the battery pack 100.The first thermally conductive layer 124 further provides increased durability to the battery pack 100. The first thermally conductive layer 124 transfers the heat from the plurality of cells 114 to the plurality of fins 122 through the conduction process.The first thermally conductive layer 124 further resists movements of the plurality of the cells 114 in the battery pack 100. The first thermally conductive layer 124 is configured to reduce the heat of the plurality of cells 114 by transferring the heat to the plurality of fins 122. The plurality of fins 122 is positioned on the outer walls of the top battery casing 110, and the bottom battery casing 102.
At step 304, In one embodiment, the first thermally conductive layer 124 is poured to the predetermined height of the bottom battery casing 102 of the battery pack 100, then the first cell holder 112, and the plurality of cells 114 dipped into the bottom battery casing 102 of the battery pack 100 by using a jig. The first cell holder 112, and the plurality of cells 114 dipped into the bottom battery casing 102 of the battery pack 100 in such a way that the first thermally conductive layer 124 is facing the axial surface of the plurality of cells 114.
In another embodiment, the first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 then the first thermally conductive layer 124 is poured to the predetermined height of the bottom battery casing 102 of the battery pack 100. The first cell holder 112, and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100 in such a way that the first thermally conductive layer 124 is facing the axial surface of the plurality of cells 114. In one embodiment, the plurality of cell holder sleeves 118 may include, but not limited to, a plurality of cell holder spacers, and a plurality of cell holder supporters.
At step 306, filling a second thermally conductive layer 126 on top of the first thermally conductive layer 124. The second thermally conductive layer 126 may include a phase change material (PCM). In one embodiment, the phase change material may include, but not limited to, organic phase change materials or inorganic phase change materials. The second thermally conductive layer 126 is facing the circumferential surface of the plurality of cells 114 to absorb the heat from the plurality of cells 114. In one embodiment, the second thermally conductive layer 126 is dispensed (as a liquid) in such a way that the second thermally conductive layer 126 is facing the radial surface of the plurality of cells 114. The second thermally conductive layer 126 spreads across the battery pack 100 and maintains the equal space between the plurality of cells 114.
At step 308, positioning a second cell holder 116 between the first cell holder 112 and a third cell holder 120 by sliding through, and tight fit to the plurality of cells 114 to maintain a predetermined gap between the second cell holder 116 and the second thermally conductive layer 126. Furthermore, the predetermined gap is filled by the second thermally conductive layer 126 when the second thermally conductive layer 126 is changed to a liquid state by absorbing the heat from the plurality of cells 114, and the battery pack 100. Due to the phase change process of the second thermally conductive layer 126, the state of the second thermally conductive layer 126 is changed from a solid state to the liquid state by absorbing the heat from the plurality of cells 114 and the battery pack 100.The predetermined gap is configured to provide space for volumetric expansion of the second thermally conductive layer 126, and one or more gases are generated at the time of the phase change process. The predetermined gap is configured to reduce the thermal pressure of the battery pack 100 by providing the space for volumetric expansion of the second thermally conductive layer 126, and the one or more gases generated at the time of the phase change process.
The predetermined gap is positioned on the top of the second thermally conductive layer 126. In one embodiment, the second cell holder 116 may include, but not limited to, a thermally conductive material and an electrically insulative material. In another embodiment, the second cell holder 116 may include, but not limited to, a synthetic polymer-based material, a non-synthetic polymer-based material, and a thermoset plastic material. Further, the second cell holder 116 is configured to provide a predetermined space between the plurality of cells 114. In one embodiment, the second cell holder 116 is configured to provide structural rigidity to the battery pack 100. In another embodiment, the second cell holder 116 is configured to reduce shock and vibration. In one embodiment, the second cell holder 116 is configured to maintain the size of the predetermined air gap as per the design.
At step 310, filling the thermally isolative layer 128 on top of the second cell holder 116. In one embodiment, the thermally insulative layer 128 may include, but not limited to, a silicon foam, a foam, or a polyurethane foam. In one embodiment, the thermally insulative layer 128 may include, but not limited to, a low-density thermal conductive material, and an electrically insulating material. The thermally insulative layer 128 is configured to reduce shock and vibration. The thermally insulative layer 128 may include a flame-retardant capacity.The thermally insulative layer 128 is configured to suppress fire during the thermal runaway of the plurality of cells 114 and reduce shock and vibration. The thermally insulative layer 128 is dispensed on the second cell holder 116.
In another embodiment, the thermally insulative layer 128 may include, but not limited to, a polyurethane, a polystyrene, a silicon, and a polyisocyanurate. The thermally insulative layer 128 may include, but not limited to, a high-density thermal conductive material, and an electrically insulating material. The thermally insulative layer 128 is configured to reduce shock and vibration. The thermally insulative layer 128 may include a flame retardant capacity. The thermally insulative layer 128 is configured to prevent thermal runaway/and reduce shock and vibration.The thermally insulative layer 128 is configured to reduce the heat of the plurality of cells 114. In one embodiment, the thermally insulative layer 128 is dispensed in such a way that the thermally insulative layer 128 covers the surface of the plurality of cells 114.
At step 312, placing the third cell holder 120 on top of the thermally insulative layer 128. The third cell holder 120 is positioned on the top of the thermally insulative layer 128. In one embodiment, the third cell holder 120 may include, but not limited to, a thermally conductive material and an electrically insulative material. In another embodiment, the third cell holder 120 may include, but not limited to, a synthetic polymer-based material, a non-synthetic polymer-based material, and a thermoset plastic material. Further, the third cell holder 120 is configured to provide the equal space between the plurality of cells 114. In one embodiment, the third cell holder 120 is configured to provide structural rigidity to the battery pack 100. In another embodiment, the third cell holder 120 is configured to reduce shock and vibration.
At step 314, connecting different polarities of the plurality of cells 114 using the plurality of connectors by an interconnector 106.In one embodiment, the plurality of connectors may be feeders. In another embodiment, the plurality of connectors may include, but not limited to, one or more conducting elements. In yet another embodiment, the plurality of connectors may include, but not limited to, a nickel strip.The interconnector 106 is positioned on top of the third cell holder 120, and the plurality of cells 114.
At step 316, stacking a thermal interface material 108 on top ofthe plurality of connectors. In one embodiment, the thermal interface material 108 may include, but not limited to, a thermal pad, a thermal paste, a silicon pad, a gap pad, a thermal grease, a thermal gap filler, and the like. In one embodiment, the thermal interface material 108 may be applied above the plurality of connectors. In another embodiment, the thermal interface material 108 may be pasted above the plurality of connectors. In yet another embodiment, the thermal interface material 108 may be dispensed above the plurality of connectors.
At step 318, receiving the heat generated from the battery pack 100 through the conduction process by the thermal interface material 108.In one embodiment, the thermal interface material 108 may include, but not limited to, an electrically insulative material. In one embodiment, the thermal interface material 108 may include, but not limited to, a thermal pad, a thermal paste, a silicon pad, a gap pad, a thermal grease, a thermal gap filler, and the like.
At step 320, transferring the heat generated from the battery pack 100 to a top battery casing 110 by the thermal interface material 108. The thermal interface material 108 is positioned on the top of the first cell holder 112, and the plurality of cells 114. The thermal interface material 108 is compressed by the top battery casing 110 to transfer the heat which is generated from the plurality of cells 114, and the interconnector 106.
In one embodiment, the first cell holder 112 and the plurality of cells 114 are placed into the bottom battery casing 102 of the battery pack 100. The first thermally conductive layer 124 is poured to the predetermined height in the bottom battery casing 102 of the battery pack 100. The first thermally conductive layer 124 is facing the axial surface and circumferential surface of the plurality of cells 114 to absorb the heat from the plurality of cells 114 and transfer the heat to the plurality of fins 122.
In one embodiment, the predetermined gap is provided between the second cell holder 116 and the second thermally conductive layer 126. Due to the phase change process of the second thermally conductive layer 126, the state of the second thermally conductive layer 126 is changed from a solid state to a liquid state by absorbing the heat from the plurality of cells 114 and the battery pack 100. The predetermined gap is configured to provide space for volumetric expansion of the second thermally conductive layer 126, and one or more gases are generated at the time of the phase change process. The predetermined gap is configured to reduce the thermal pressure of the battery pack 100 by providing space for volumetric expansion of the second thermally conductive layer 126, and the one or more gases generated at the time of the phase change process.
Improvements and modifications may be incorporated herein without deviating from the scope of the invention. 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 appended claims.

LIST OF REFERENCE NUMERALS

100: Battery pack
102: Bottom battery casing
106: Interconnector
108: Thermal interface material
110: Top battery casing
112: First cell holder
114: Plurality of cells
116: Second cell holder
118: Plurality of cell holder sleeves
120: Third cell holder
122: Plurality of fins
124: First thermally conductive layer
126: Second thermally conductive layer
128: Thermally isolative layer
,CLAIMS:
1. A battery pack (100) comprising: a first thermally conductive layer (124) is configured to spread across the battery pack (100), and maintain an equal space between a plurality of cells (114), wherein the first thermally conductive layer (124) is filled to a predetermined height in a bottom battery casing (102), wherein the first thermally conductive layer (124) is facing an axial surface and a circumferential surface of the plurality of cells (114) to absorb heat from the plurality of cells (114) and transfer the heat to a plurality of fins (122); a second thermally conductive layer (126) is configured to spread across the battery pack (100) and maintain an equal space between the plurality of cells (114), wherein the second thermally conductive layer (126) is facing the circumferential surface of the plurality of cells (114) to absorb the heat from the plurality of cells (114), wherein the second thermally conductive layer (126) is positioned on a top of the first thermally conductive layer (124); a thermally isolative layer (128) is configured to prevent thermal runaway, and reduce shock and vibration, wherein the thermally isolative layer (128) is filled on a top portion of a second cell holder (116), wherein the thermally isolative layer (128) is configured to suppress fire during the thermal runaway of the plurality of cells (114); a first cell holder (112) comprises a plurality of cavities and is configured to hold the plurality of cells (114) in a predetermined position, wherein the first cell holder (112) is configured to provide an equal space between the bottom battery casing (102) and a bottom surface of the plurality of cells (114); the second cell holder (116) is positioned between the first cell holder (112) and a third cell holder (120) by sliding through, and tight fit to the plurality of cells (114) to maintain a predetermined gap between the second cell holder (116) and the second thermally conductive layer (126), wherein the second cell holder (116) is configured to provide an equal space between the plurality of cells (114); a plurality of cell holder sleeves (118) configured to support and hold at least one of the first cell holder (112), the second cell holder (116), and the third cell holder (120) along with the plurality of cells (114); the third cell holder (120) is placed above the thermally isolative layer (128) and is configured to provide an equal space between the plurality of cells (114).

2. The battery pack (100) as claimed in claim 1, wherein the first thermally conductive layer (124) comprises a resin, a polymeric/non-polymeric material, a polyurethane, an epoxy, a dielectric, solid PCM, and a silicon.

3. The battery pack (100) as claimed in claim 1, wherein the second thermally conductive layer (126) comprises a phase change material (PCM), wherein the phase change material comprises organic phase change materials or inorganic phase change materials.

4. The battery pack (100) as claimed in claim 1, wherein the thermally insulative layer (128) comprises a silicon foam, a foam, a polyurethane foam, a polyurethane, a polystyrene, a silicon, and a poly is ocyanurate.

5. The battery pack (100) as claimed in claim 1, wherein the battery pack (100) further comprises an interconnector (106), wherein the interconnector (106) is configured to connect different polarities of the plurality of cells (114) by using a plurality of connectors and is positioned on a top portion of the third cell holder (120), and the plurality of cells (114).

6. The battery pack (100) as claimed in anyone of the claim above wherein; the predetermined gap is filled with one or more gases to maintain thermal and chemical stability of the battery pack (100).

7. A method (300) of thermal management in a battery pack (100) comprising: filling a first thermally conductive layer (124) to a predetermined height of a bottom battery casing (102); dipping, using a jig, a first cell holder (112), and a plurality of cells (114) into the bottom battery casing (102) of the battery pack (100); filing a second thermally conductive layer (126) on a top of the first thermally conductive layer (124); positioning a second cell holder (116) between the first cell holder (112) and the third cell holder (120) by sliding through, and tight fit to the plurality of cells (114) to maintain a predetermined gap between the second cell holder (116) and the second thermally conductive layer (126); filing a thermally isolative layer (128) above the second cell holder (116); placing the third cell holder (120) on top of the thermally isolative layer (128); connecting, by an interconnector (106), different polarities of the plurality of cells (114) using a plurality of connectors; stacking a thermal interface material (108) on a top portion of the plurality of connectors; receiving, by the thermal interface material (108), heat generated from the battery pack (100) through the conduction process; and transferring, the thermal interface material (108), and the heat generated from the battery pack (100) to a top battery casing (110).

8. A method (300) of thermal management in a battery pack (100) comprising: placing the first cell holder (112), and the plurality of cells (114) into the bottom battery casing (102) of the battery pack (100); pouring the first thermally conductive layer (124) to the predetermined height of the bottom battery casing (102) of the battery pack (100); filing a second thermally conductive layer (126) on a top of the first thermally conductive layer (124); positioning a second cell holder (116) between the first cell holder (112) and the third cell holder (120) by sliding through, and tight fit to the plurality of cells (114) to maintain a predetermined gap between the second cell holder (116) and the second thermally conductive layer (126); filing a thermally isolative layer (128) above the second cell holder (116); placing the third cell holder (120) on top of the thermally isolative layer (128); connecting, by an interconnector (106), different polarities of the plurality of cells (114) using a plurality of connectors; stacking a thermal interface material (108) on a top portion of the plurality of connectors; receiving, by the thermal interface material (108), heat generated from the battery pack (100) through the conduction process; and transferring, the thermal interface material (108), and the heat generated from the battery pack (100) to a top battery casing (110).


9. The method (300) as claimed inclaim 7 or 8, wherein the first thermally conductive layer (124) comprises a resin, a polymeric/non-polymeric material, a polyurethane, an epoxy, a dielectric, solid PCM, and a silicon.


10. The method (300) as claimed in 7 or 8, wherein the second thermally conductive layer (126) comprises a phase change material (PCM), wherein the phase change material comprises organic phase change materials or inorganic phase change materials.

11. The method (300) as claimed in 7 or 8, wherein the thermally insulative layer (128) comprises a silicon foam, a foam, a polyurethane foam, a polyurethane, a polystyrene, a silicon, and a poly is ocyanurate.

12. The method (300) as claimed in 7 or 8, wherein the method (300) comprises: providing the predetermined gap for filling one or more gases to maintain thermal and chemical stability of the battery pack (100).