Description:AN ENERGY STORAGE UNIT WITH ACTIVE COOLING AND A METHOD OF ASSEMBLY THEREOF
FIELD OF THE INVENTION
[0001] The present subject matter is related, in general to a vehicle, and more particularly, but not exclusively to a cooling system for an energy storage unit and a method of assembly thereof.
BACKGROUND OF THE INVENTION 5
[0002] Recently there is a growing reliance on electrical energy for various electronic equipment and the development of electric vehicles. With the increasing utility of electrical energy, there is a need for effective energy storage systems to fully utilize its benefits. These systems must also be equipped with safety mechanisms to handle any malfunctions that may occur. In recent years, there has 10 been significant research and development in the field of electric mobility, particularly in relation to electric and plug-in hybrid vehicles. The demands of this field require efficient monitoring and diagnosis of issues like thermal runaway, short circuits, and other electrical malfunctions that can occur within the energy storage system. Additionally, the energy storage systems used in mobility 15 applications need to be rechargeable for repeated use.
[0003] An energy storage system typically consists of a battery pack composed of multiple cells or battery modules. These cells or modules store electrical energy and supply it to an external load, which draws energy from the battery pack for its operation. One of the popular type of energy storage system is the lithium-ion 20 battery, known for its high energy density, high power density, excellent cycle performance, and environmental friendliness. However, a significant drawback of lithium-ion cells is their tendency to undergo uncontrolled exothermic reactions during thermal runaway. Thermal runaway refers to the accelerated release of heat from a cell due to an uncontrollable exothermic reaction. In this process, the cell 25 loses its ability to dissipate heat as quickly as it is generated, resulting in a loss of thermal stability. This can cause the heat to propagate to neighbouring cells or
3
nearby electrical and electronic equipment. If one cell fails, it can lead to damage to other cells and significantly impact the safety and performance of the entire battery pack, potentially causing severe accidents.
[0004] Cells in the battery pack generate heat during the charging and discharging process, and this heat production can be due to various factors such as overcharging, 5 frozen electrolyte, damaged cells, or low electrolyte levels. Moreover, the assembly, manufacturing, and tab welding processes can introduce risks of short circuits, which can cause cell failure and the release of hot gases. In a battery pack consisting of multiple stacked cells, these hot gases generated by a failed cell can affect the integrity of neighbouring cells and cause damage to other critical 10 components positioned near the failed cells.
[0005] The heat generated during the charging/discharging process, cell short circuit, and battery pack operation can lead to thermal runaway, jeopardizing the entire pack. To prevent the failure of cells from affecting others and avoid the burning of the battery pack and the vehicle, it is crucial to prevent thermal 15 propagation between cells and maintain a lower overall temperature for the battery pack. Poor thermal management inside lithium-ion battery packs, especially in electric vehicles (EVs) and hybrid electric vehicles (HEVs), has become a significant concern due to the risk of fire hazards.
[0006] Various methods have been proposed in prior art to address thermal 20 management within battery packs. These include the use of phase change materials, gap fillers, thermal conducting pastes, or thermal pads as a single medium for thermal management. However, these existing methods have limitations in providing an effective and efficient thermal management mechanism within the battery pack, or energy storage unit. The limitation is primarily due to the reason 25 that, that the latent heat of the Phase change material (PCM) possesses a high latent heat, enabling it to absorb a significant amount of heat and undergo a phase change while maintaining a constant cell temperature. This can effectively maintain a lower cell temperature and control the self-heating rate of the cell, while mitigating the risk of thermal degradation and thermal runaway. However, once the latent heat is 30
4
reached by the PCM, the heat of the energy module can spike uncontrollably causing hazard and threat of explosion. Therefore, there is a need for an improved power source unit that can prevent thermal propagation between cells, enhance cooling of the power source units, and overcome the limitations and challenges faced by previous approaches. 5
[0007] Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of described systems with some aspects of the present disclosure, as set forth in the remainder of the present application and with reference to the drawings.
SUMMARY 10
[0008] As per an embodiment of the present invention, an energy storage unit comprising: a plurality of cells, the plurality of cells being electrically connected to each other; a casing configured to house the plurality of cells. In an embodiment, the casing comprises a top cover, a bottom cover, and a box comprising a plurality of side walls; and a first cooling material configured to provide a structural support 15 to the plurality of cells in the casing. In an embodiment, the first cooling material being disposed adjacent to the bottom cover.
[0009] As per an embodiment of the present invention, the energy storage unit comprises a second cooling material being configured to be in contact with at least a portion of each of the plurality of cells and further being in thermal contact with 20 the first cooling material.
[00010] As per an embodiment of the present invention, at least the portion of the plurality of cells includes a bottom portion of each of the plurality of cells.
[00011] As per an embodiment of the present invention, the first cooling material being disposed between a plate and the top cover of the casing. In an embodiment, 25 the plate is thermally conducting and electrically insulating.
[00012] As per an embodiment of the present invention, the plate is sandwichly disposed between the first cooling material and a plurality of interconnectors connecting each of the plurality of cells.
5
[00013] As per an embodiment of the present invention, the first cooling material being disposed along the plurality of side walls of the casing and being in contact with at least side portions of the plurality of cells.
[00014] As per an embodiment of the present invention, the first cooling material being a foam material having a plurality of cavities. In an embodiment, the second 5 cooling material being a phase change material. In an embodiment, the foam material being made of a metal.
[00015] As per an embodiment of the present invention, each of the plurality of cavities is configured to structurally support at least the bottom portion of each of plurality of cells. 10
[00016] As per an embodiment of the present invention, the first cooling material being adhesively disposed adjacent to the corresponding portion of the casing.
[00017] As per an embodiment of the present invention, the plurality of cells being covered by an electrical insulation layer covering a surface area of each cell of the plurality of cells. 15
[00018] As per an embodiment of the present invention, a method for manufacturing of an energy storage unit comprising the steps of: disposing, a plurality of cells in a casing comprising a top cover, a bottom cover, and a box comprising a plurality of side walls; disposing, a first cooling material being adjacent to the bottom cover; supporting, at least the bottom portion of each of the 20 plurality of cells in a plurality of cavities of the first cooling material; connecting, each of the plurality of cells by a plurality of interconnectors connecting; covering, the top portion of the energy storage unit by the top cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[00019] The present invention will become more fully understood from the detailed 25 description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
6
[00020] Figure 1 exemplarily illustrates an exploded top perspective view of an energy storage unit.
[00021] Figure 2 exemplarily illustrates an exploded bottom perspective view of an energy storage unit.
[00022] Figure 3 exemplarily illustrates an exploded side perspective view of an 5 energy storage unit.
DETAILED DESCRIPTION
[00023] The present disclosure may be best understood with reference to the detailed figures and description set forth herein. Various embodiments are discussed below with reference to the figures. However, those skilled in the art will 10 readily appreciate that the detailed descriptions given herein with respect to the figures are simply for explanatory purposes as the methods and systems may extend beyond the described embodiments. For example, the teachings presented and the needs of a particular application may yield multiple alternative and suitable approaches to implement the functionality of any detail described herein. Therefore, 15 any approach may extend beyond the particular implementation choices in the following embodiments described and shown.
[00024] References to “one embodiment,” “at least one embodiment,” “an embodiment,” “one example,” “an example,” “for example,” and so on indicate that the embodiment(s) or example(s) may include a particular feature, structure, 20 characteristic, property, element, or limitation but that not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Further, repeated use of the phrase “in an embodiment” does not necessarily refer to the same embodiment.
[00025] The present invention now will be described more fully hereinafter with 25 different embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather those embodiments are provided so that this disclosure will be
7
thorough and complete, and fully convey the scope of the invention to those skilled in the art.
[00026] The object of the present subject invention is to provide an energy storage unit which has a cooling material that enable an efficient thermal management mechanism in the energy storage unit. The energy storage unit comprises a plurality 5 of cells which are electrically connected to each other. During operation, each of the plurality of cell emits heat, which eventually increases the temperature of the entire energy storage unit. Therefore, to provide efficient and optimum cooling, the present invention provides a first cooling material which disposed at a bottom portion of each of the plurality of cells. Thus, the heat which is generated by the 10 each of the plurality of cells is absorbed by the first cooling material, which is further transmitted to the outer casing.
[00027] Further objective of the present invention is to efficient thermal management mechanism in the energy storage unit without compromising the weight of the energy storage unit, and complexity of assembly. Inline with the same, 15 the present invention provides energy storage unit comprising the first cooling material which in addition to cooling of the plurality of cells, also provides structural support to the bottom portion of each of plurality of cells. This advantageously eliminates need of a battery holder at the bottom portion.
[00028] Further, the objective of the present invention is to provide enhanced 20 cooling to the energy storage unit. Thereby the present invention provides a second cooling material which is in thermal contact with the first cooling material, thus the first cooling material along with second cooling material delay the onset of thermal runaway in case the cell goes into thermal runaway – thereby allowing sufficient time for evacuation/ warning to the user. 25
[00029] The aforesaid and other advantages of the present subject matter would be described in greater detail in conjunction with the figures & embodiment in the following description.
8
[00030] Figure 1 exemplarily illustrates an exploded top perspective view of an energy storage unit 100. The energy storage unit 100 comprises includes plurality of cells 106 which are electrically to each other through a plurality of interconnectors 104. Further, each of the plurality of cells 106are insulated to each to prevent short circuiting by an electrical insulation layer covering a surface area 5 of each cell of the plurality of cells. Each of the plurality of cells 106 are housed in a casing 102 which protects plurality of cells 106 from outside environment and prevents it from getting damaged. The plurality of cells 106 are disposed in one or more holder to hold it still in its required position, during the operation of the vehicle (not shown) and also to maintain the required cell arrangement and cell 10 spacing. In the present embodiment, the casing 102 includes a top cover 102a, a box 102b, and a bottom cover 102c. The box 102b supports the one or more sides of the energy storage unit 100. The top cover 102a covers the energy storage unit 100 from a top portion. The bottom cover 102c provides a support to the energy storage unit 100 from the bottom portion. In an embodiment, the casing 102 can be 15 one of the aluminum casings.
[00031] Figure 2 exemplarily illustrates an exploded bottom perspective view of an energy storage unit 100. Figure 3 exemplarily illustrates an exploded side perspective view of an energy storage unit 100. The figure 2 and figure 3 are explained together for brevity. For enabling active and optimum thermal 20 management, the energy storage unit 100 comprises a first cooling material. The first cooling material 206is disposed adjacent to the bottom cover 102c of the casing 102. The first cooling material 206is a foam material having a plurality of cavities 206a. As per an embodiment, the first cooling material 206 is made of a heat conducting material such as a metal. As per an embodiment, the first cooling 25 material 206 is made of a copper foam. The plurality of cavities 206a of the first cooling material 206 provide structural support to the plurality of cells 106from the bottom portion the plurality of cells. In other, words the first cooling material 206 in addition to transmitting heat from the plurality of cells 106, also provides support or holding to the bottom portion of the plurality of cells. Thus, the first cooling 30
9
material 206 enables to eliminate the need of the bottom holder from the energy storage unit.
[00032] Further, the energy storage unit 100 comprises a second cooling material. As per an embodiment the second cooling material (not shown) is a phase change material (PCM). The phase change material is in contact with the surface area of 5 each of the plurality of cell. Further, the PCM is thermally in contact with the first cooling material. Thus, when any of the plurality of cells 106 starts to heat up, the heat is transmitted through both the first and the second cooling materials. This enables to maintain the temperature of the energy storage unit 100 optimally. Further, even if any of the cell undergoes thermal run away, the combination of the 10 first and the second cooling materials provides a time to take appropriate action by a user.
[00033] As per an embodiment of the present invention, the first cooling material 206 is disposed around the top portion of the plurality of cells. As per an aspect of the present invention, the top portion of the plurality of cells 106are connected by 15 plurality of interconnectors 104. To prevent the short circuiting between the plurality of interconnectors 104 first cooling material 206 made of metal foam, a plate 202 is sandwichly disposed between the first cooling material 206 and a plurality of interconnectors 104. The plate 202 is configured to have thermally conducting and electrically insulating properties. The first cooling material 206 is 20 disposed between the plate 202 and the top cover 102a of the casing 102.
[00034] As per yet another embodiment of the present invention, the first cooling material 206 is disposed along the plurality of side walls of the casing 102, and it is being in contact with at least side portions of the plurality of cells. In other words, the first cooling material 206 is disposed between the box 102b, and the side surface 25 of the plurality of cells. As per an embodiment of the present invention, the first cooling material 206 is adhesively disposed adjacent to covers of the casing 102.
[00035] As per an aspect of the present invention, a method of manufacturing or assembling the energy storage unit 100 comprises the steps of disposing, a plurality of cells 106in a casing 102 comprising a top cover 102a, a bottom cover 102c, and 30
10
a box 102b comprising a plurality of side walls. Thereafter, a first cooling material 206 is disposed adjacent to the bottom cover 102c for holding or supporting the bottom portion of the plurality of cells 106in the plurality of cavities 206a of the first cooling material. Further, each of the plurality of cells 106is connected to each other by the plurality of interconnectors 104. Finally, injecting the second cooling 5 material into the energy storage unit 100 and covering the top portion of the energy storage unit 100 by a top cover 102a.
[00036] The present invention advantageously provides an energy storage unit 100 comprising the first cooling material 206 configured to provide a structural support to the plurality of cells 106 in the casing 102. In an embodiment, the first cooling 10 material 206 being disposed adjacent to the bottom cover 102c. This enables the first cooling material 206 to effectively maintain an optimum temperature of the energy storage unit 100 along with providing support to the plurality of cells. Thus, need of an additional holder for the plurality of cells 106 is eliminated, thereby provide ease of manufacturing, reduced weight, cost of production. 15
[00037] Also, the present invention advantageously provides that the energy storage unit 100 comprises a second cooling material, which is phase change material. Thus, contribution of the first and the second cooling material enables to effectively manage temperature of the energy storage unit. Further, even in case any one of the plurality of cells 106 undergoes thermal runaway, the present invention 20 enables to delay the hazard if any, or it provide time to the user to taking certain actions.
[00038] The first cooling material 206 is a metallic foam, which is a good thermal conductor. Thus, the temperature from each of the plurality of the cells is transmitted easily by the first cooling material 206 to the outside of the casing 102. 25 Further, the foam material of the first cooling material 206 assists in reducing weight, and enable easily escape of hot gases from inside of the casing 102 to the outside atmosphere.
[00039] Further advantageously, In an embodiment, the first cooling material 206 is disposed on the top portion of the energy storage unit, the plate 202 prevents 30
11
direct contact between the plurality of interconnectors 104, and the first cooling material. Since the first cooling material 206 is made of a metallic foam, thus the plate 202 prevent short circuiting of the energy storage unit.
[00040] In light of the above mentioned advantages and the technical advancements provided by the disclosed method and system, the claimed steps as discussed above 5 are not routine, conventional, or well understood in the art, as the claimed steps enable the following solutions to the existing problems in conventional technologies. Further, the claimed steps clearly bring an improvement in the functioning of the battery pack itself as the claimed steps and constructional features provide a technical solution to a technical problem. 10
[00041] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter and is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the 15 embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
[00042] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are 20 not intended to be limiting, with the true scope and spirit being indicated by the following claims.
[00043] A person with ordinary skills in the art will appreciate that the systems, modules, and sub-modules have been illustrated and explained to serve as examples and should not be considered limiting in any manner. It will be further appreciated 25 that the variants of the above disclosed system elements, modules, and other features and functions, or alternatives thereof, may be combined to create other different systems or applications.
12
[00044] Those skilled in the art will appreciate that any of the aforementioned steps and/or system modules may be suitably replaced, reordered, or removed, and additional steps and/or system modules may be inserted, depending on the needs of a particular application. In addition, the systems of the aforementioned embodiments may be implemented using a wide variety of suitable processes and 5 system modules, and are not limited to any particular computer hardware, software, middleware, firmware, microcode, and the like. The claims can encompass embodiments for hardware and software, or a combination thereof.
[00045] While the present disclosure has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes 10 may be made and equivalents may be substituted without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. Therefore, it is intended that the present disclosure is not limited to the particular embodiment disclosed, but that the present disclosure will 15 include all embodiments falling within the scope of the appended claims.
13
List of reference numerals:
100: Energy storage unit
102: casing
102a: Top cover
102b: Box 5
102c: Bottom cover
104: Plurality of interconnectors
106: Plurality of cells
202: Plate
206: First cooling material 10
206a: Plurality of cavities , Claims:CLAIMS
I/We claim:
1. An energy storage unit (100), the energy storage unit (100) comprising:
a plurality of cells (106), the plurality of cells (106) being electrically connected to each other; 5
a casing (102) configured to house the plurality of cells, wherein the casing (102) comprises a top cover (102a), a bottom cover (102c), and a box (102b) comprising a plurality of side walls; and
a first cooling material (206) configured to provide a structural support to the plurality of cells (106) in the casing (102), wherein the first 10 cooling material (206) being disposed adjacent to the bottom cover (102c).
2. The energy storage unit as claimed in claim 1, wherein the energy storage unit (100) comprises a second cooling material being configured to be in contact with at least a portion of each of the plurality of cells (106) and 15 further being in thermal contact with the first cooling material (206).
3. The energy storage unit (100) as claimed in claim 2, wherein at least the portion of the plurality of cells (106) includes a bottom portion of each of the plurality of cells (106). 20
4. The energy storage unit (100) as claimed in claim 1, wherein the first cooling material (206) being disposed between a plate 202 and the top cover (102a) of the casing (102), wherein the plate (202) is thermally conducting and electrically insulating. 25
5. The energy storage unit (100) as claimed in claim 1, wherein the plate (202) is sandwichly disposed between the first cooling material (206) and a plurality of interconnectors (104) connecting each of the plurality of cells (106). 30
15
6. The energy storage unit (100) as claimed in claim 1, wherein the first cooling material (206) is disposed along the plurality of side walls of the casing (102) and being in contact with at least side portions of the plurality of cells (106). 5
7. The energy storage unit (100) as claimed in claim 1, wherein the first cooling material (206) is a foam material having a plurality of cavities (206a), wherein the second cooling material being a phase change material, wherein the foam material being made of a metal. 10
8. The energy storage unit (100) as claimed in claim 7, wherein each of the plurality of cavities (206a) is configured to structurally support at least the bottom portion of each of plurality of cells (106).
15
9. The energy storage unit (100) as claimed in claim 1, wherein the first cooling material (206) being adhesively disposed adjacent to the corresponding portion of the casing (102).
10. The energy storage unit (100) as claimed in claim 1, wherein the plurality 20 of cells (106) being covered by an electrical insulation layer covering a surface area of each cell of the plurality of cells (106).
11. A method for manufacturing of an energy storage unit (100) wherein the method comprising the steps of: 25
disposing, a plurality of cells (106) in a casing (102) comprising a top cover (102a), a bottom cover (102c), and a box (102b) comprising a plurality of side walls;
disposing, a first cooling material (206) adjacent to the bottom cover (102c); 30
supporting, at least the bottom portion of each of the plurality of cells (106) in a plurality of cavities (206a) of the first cooling material;
16
connecting, each of the plurality of cells (106) by a plurality of interconnectors connecting;
covering, the top portion of the energy storage unit (100) by the top cover (102a).
5
12. The method as claimed in claim 11, wherein injecting a second cooling material into the casing (102) before covering the top portion of the energy storage unit (100).
13. The method as claimed in claim 11, wherein using an adhesive layer 10 between the first cooling material (206) and the corresponding portion of the casing (102).
14. The method as claimed in claim 11, wherein the first cooling material (206) being disposed between a plate (202) and the top cover (102a) of the casing 15 (102), wherein the plate (202) is thermally conducting and electrically insulating.
15. The method as claimed in claim 11, wherein the plate (202) is sandwichly disposed between the first cooling material (206) and a plurality of 20 interconnectors (104) connecting each of the plurality of cells (106).
16. The method as claimed in claim 11, wherein the first cooling material (206) being disposed along the plurality of side walls of the casing (102) and being in contact with at least side portions of the plurality of cells (106). 25
17. The method as claimed in claim 11, wherein the second cooling material being a phase change material, wherein the foam material being made of a metal.
30
17
Dated this 27th day of July 2023