Description:TECHNICAL FIELD
5 [0001] The present subject matter relates generally to a battery pack. More particularly but not exclusively the present subject matter relates to structure of the battery pack.

BACKGROUND
10 [0002] With the advancement in technology, an electric or hybrid electric vehicle makes use of one or more power sources to drive the vehicle. The one or more powers source is a battery pack to provide power to run a motor which in turn runs one or more wheels of the vehicle. The one or more power sources in such hybrid electric vehicles are prone to damage due to increase in
15 temperature as the usage increases.
[0003] Lithium-ion batteries (LIBs) having the features of being a high energy density, high power density battery pack with excellent cycle performance and environmental friendliness are being widely used in electric vehicles and energy storage. However, accidents related to fires and
20 explosions of LIBs occur frequently all over the world. Some of these explosions have caused serious threats to human life and health.
[0004] The battery pack includes a plurality of cells, where the plurality of cells forms a cell module. The cell module is accommodated inside a cavity defined within said battery pack casing. Existing battery packs are constrained by the battery pack casing. When a Lithium-ion battery pack is charged, it causes the electrodes to expand. The expansion results in added mechanical stress on the electrodes and the battery pack casing. Moreover, due to the increased need of storage capacity of the battery pack, additional active anode and cathode materials are inserted into the battery pack, which further contributes to an increase in mechanical stress. Therefore, there is a compromise between performance of the battery pack and capacity of the battery pack.

[0005] Additionally, there is a risk of thermal runaway. The increase in temperature of the battery pack leads to poor performance of the vehicle and causes thermal runaway, in turn creating unsafe driving conditions for a user. Thermal runaways are caused due to an abnormal increase in temperature
5 inside the battery pack which may lead to the plurality of cells of the battery pack to explode. In case the plurality of cells is charged with high energy density, the thermal runaway is a fast, violent, self-accelerating chemical reaction of electrodes and electrolyte which releases high amounts of heat and gas.
[0006] Once the plurality of cells are in thermal runaway mode, the heat generated by the plurality of cells trigger a thermal runaway reaction, causing the battery pack to be explode, with massive destruction to peripheral devices. [0007] When thermal runaway occurs, the amount of pressure that builds inside the battery pack is exponential. This pressure is formed due to the enormous quantity of gasses being built inside during the operation of the battery pack. This pressure is directly exerted on the battery pack casing. Additionally, the orientation of the plurality of cells is such that the end tabs of the cells face the battery pack casing. Predominantly, it is through these end tabs that explosion of the plurality of cells occurs.
[0008] Therefore, the battery pack casing is required to tolerate the pressure exerted by both these events. A battery pack casing structure that has sufficient rigidity and stiffness to absorb the energy directed at it can withstand the sudden impact from explosion. The pressure built inside a battery pack can cause tremendous pressure to be exerted on the casing of the battery pack, which can lead to breakage and rupture of the battery pack. Therefore, it a requirement for the battery pack casing structure to be sufficiently elastic in nature and have enough space to plastically deform within the yield point, to not have a fracture failure.
[0009] Additionally, during the explosion of an LIB, there is a great threat to the immediate surrounding environment as well as farther surroundings of the battery. When an explosion occurs, numerous shrapnel and debris created during the explosion of the battery pack are projected and flung in all

directions, at extremely high speeds at long distances. This can cause immense damage to the user of the battery pack as well as the user’s surroundings. Therefore, there is a need for the battery pack casing to be robust and sturdy, with sufficient stiffness and rigidity of the battery pack casing is critically advantageous to the user’s health and safety.
[00010] In the known art, the battery pack casing in constructed using aluminium to improve the rigidity of the battery pack casing. To further strengthen the battery pack casing, a steel plate is inserted between the cell module and the battery pack casing. The steel plate is part of the cell module, which is placed to strengthen and reinforce the battery pack casing in case of adverse conditions.
[00011] It is important that there is good thermal conduction between the cells and the casing. As the heat propagates away from the cells, it dissipates into the environment through the casing. The addition of the steel plate forms an air gap between the steel plate and the casing of around 12 millimetres, therefore, making it difficult for heat to be dissipated efficiently. The heat generated from the cells is not able to propagate to the casing and then into the environment. Such conditions accelerate the possibilities of thermal runaway in a battery pack.
[00012] The air gap between the steep plate and the casing proves to be disadvantageous due to its poor insulating properties, since it leads to heat being trapped inside the battery pack. Since, there is an absence of a conduction path for heat to escape to the outside environment, the thermal performance of the battery pack reduces drastically, the performance decreases up to 40%-50% of the battery pack’s potential use. The risk of thermal runaway increases due to the poor conduction between the cells. [00013] Moreover, the addition of the steel plate also causes the weight of the battery pack to increase. An increased load in vehicle essentially decreases the efficiency of the vehicle as well, consequently decreasing the mileage of the vehicle.

[00014] Therefore, there is a need for a rigid and sturdy battery pack casing, which is fire resistant and prevents thermal runaway by aiding dissipation of heat into the environment.
[00015] 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
5 the drawings.

SUMMARY OF THE INVENTION
[00016] According to embodiments illustrated herein, the present invention provides a battery pack. The battery pack comprises of a casing. The casing is configured to house a plurality of cells, the casing is integrally reinforced
10 with a metal mesh structure. The metal mesh structure is made by interlinked thin wire strands, the interlinked thin wire strands creating a pre-defined pattern. The metal mesh structure is configured to structurally strengthen and support the casing of the battery pack, in order to increase the rigidity of the battery pack.
15 [00017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS
20 [00018] The details are described with reference to an embodiment of a battery pack along with the accompanying diagrams. The same numbers are used throughout the drawings to reference similar features and components.
[00019] Figure 1 exemplarily illustrates an exploded top perspective top view of a battery pack, in accordance with an embodiment of the present disclosure.
25 [00020] Figure 2 exemplarily illustrates an exploded perspective side view of the battery pack, in accordance with an embodiment of the present disclosure.

[00021] Figure 3a exemplarily illustrates a perspective view of a metal mesh structure and battery pack casing, in accordance with an embodiment of the present disclosure.
[00022] Figure 3b exemplarily illustrates a detailed view of a metal mesh
5 structure and battery pack casing as demarcated in Figure 3a, in accordance with an embodiment of the present disclosure.
[00023] Figure 4a exemplarily illustrates a perspective side view of a metal mesh structure and battery pack casing, in accordance with an embodiment of the present disclosure.
10 [00024] Figure 4b exemplarily illustrates a detailed side view of a metal mesh structure and battery pack casing as demarcated in Figure 4a, in accordance with an embodiment of the present disclosure.

15 DETAILED DESCRIPTION
[00025] Exemplary embodiments are described with reference to the accompanying drawings. Wherever convenient, the same reference numbers are used throughout the drawings to refer to the same or like parts. While examples and features of disclosed principles are described herein,
20 modifications, adaptations, and other implementations are possible without departing from the spirit and scope of the disclosed embodiments. It is intended that the following detailed description be considered as exemplary only, with the true scope and spirit being indicated by the following claims.
[00026] An objective of the present subject matter is to provide a battery pack which is sturdy and strengthened to brace the shock and impact produced due to adverse conditions of the battery pack. The present subject matter provides a rigid and sturdy battery pack casing, which is fire resistant and prevents thermal runaway by aiding dissipation of heat into the environment. The dissipation of heat reduces the probability of thermal runaway, which consequently decreases the probability of explosion of the battery pack. The present subject matter also provides a battery pack with casing that is capable

of absorbing extreme mechanical shocks that the casing could encounter during explosions, accidental impacts or during thermal runaway conditions.
[00027] The present subject matter also enables a better sealing between the joints of the casing, which further strengthens the casing of the battery pack. This also increases the tolerance of the battery pack in case of rough handling, by providing a structurally stronger batter pack than conventionally
5 manufactured battery packs. The present subject matter also provides better thermal conductivity, thus, preventing the effect of thermal runaway and ensure quicker cooling of the battery.
[00028] As per an aspect of the present subject matter, the present invention provides a battery pack. The battery pack comprises of a casing. The casing
10 is configured to house a plurality of cells, the casing is integrally reinforced with a metal mesh structure. The metal mesh structure is made by interlinked thin wire strands, the interlinked thin wire strands creating a pre-defined pattern. The metal mesh structure is configured to structurally strengthen and support the casing of the battery pack, in order to increase the rigidity of the
15 battery pack.

[00029] As per an aspect of the present subject matter, the casing of the battery pack comprises at least one of a top casing, a bottom casing, and a side casing. At least one of the top casing, the bottom casing, and the side casing comprises the metal mesh structure, which provides additional
20 structural integrity to the casing of the battery pack.

[00030] As per an aspect of the present subject matter, the plurality of cells of the battery pack forms a cell module which is accommodated inside a cavity defined within the casing.
[00031] As per an aspect of the present subject matter, during casting of the
25 casing the metal mesh structure is inserted in a die used for the casting of the casing. The metal mesh structure is sandwichedly disposed between layers of an alloy material which is used for casting of the casing. The alloy material forms a matrix structure and occupies the spaces present in the interlinked

thin wire strands of the metal mesh structure thereby forming a solid structure for the casing.
[00032] As per an aspect of the present subject matter, the metal mesh structure is made of steel, therefore, aiding in absorption of mechanical shock
5 and increasing the rigidity of the casing of the battery pack.

[00033] As per an aspect of the present subject matter, the interlinked thin wire strands are of uniform cross-sectional area, providing uniform strength across all regions of the casing, and decreasing the complexity of manufacturing of the metal mesh structure.
10 [00034] As per an aspect of the present subject matter, the interlinked thin wire strands are of varying cross-sectional area in one or more pre-defined regions of the casing. These pre-defined regions of the casing are regions that are fracture-prone and exposed to maximum impact during adverse conditions. The interlinked thin wire strands are of greater cross-sectional
15 area in the fracture-prone regions of the casing, thereby optimising the structure integrity of the casing.
[00035] As per an aspect of the present subject matter, the casing is made of an alloy material comprising at least one of ADC12, or ADC6. The casing may also be manufactured using alloy materials generally known in the art.
20 [00036] As per an aspect of the present subject matter, the metal mesh structure is manufactured using at least one of a casting process, a forming process, or a combination thereof.
[00037] As per an aspect of the present subject matter, the pre-defined pattern comprises a polygonal shaped interlinked pattern. The polygonal shape may
25 be any one of a rectangle, a parallelogram, an octagonal, a circle, or the like. The polygonal shape may be determined based on the requirements of the battery pack.
[00038] As per an aspect of the present subject matter, the battery pack also comprises a Battery Management System (BMS). The BMS is mounted on
30 the cell module using one or more studs. These one or more studs ensure that

sufficient distance is maintained between the BMS board and the cell module, to prevent damaging of the BMS during adverse conditions of the battery pack.
[00039] The embodiments of the present invention will now be described in
5 detail with reference to a battery pack along with the accompanying drawings. However, the present invention is not limited to the present embodiments. The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various
10 arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
15 [00040] Figure 1 exemplarily illustrates an exploded top perspective view of a battery pack 100. Figure 2 exemplarily illustrates an exploded perspective side view of the battery pack, in accordance with an embodiment of the present disclosure. For the sake of brevity, Figure 1 and Figure 2 are explained together.
20 [00041] A battery pack casing 102 protects one or more cell modules 104 from outside environment and prevents it from getting damaged. The cell module 104 includes plurality of cells 106 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 spacing.
25 The battery module 104 includes the plurality of cells 106, one or more cell holder, and one or more interconnectors. The plurality of cells 106 provides the electric energy to drive a vehicle (not shown). The one or more interconnectors are used to make electrical connection between the plurality of cells 106. In the present embodiment, the casing 102 includes a top casing
30 102a, a side casing 102b, and a bottom casing 102c. The side casing 102b
supports the one or more sides of the battery pack. The top casing 102a covers

the battery pack from a top portion. The bottom casing 102c provides a support to the battery pack. In an embodiment, the casing 102 can be one of the aluminum casings.
[00042] The one or more stud 204 is sandwichedly disposed between the cell
5 module 104 and the Battery Module Management System 202. In the present embodiment, the one or more studs 204 act as an insulation member between the cell module 104 and the Battery Module Management System 202. In an embodiment, the BMS 202 is disposed on a base member 206, which is disposed on the cell module 104. The one or more studs 204 ensure that
10 sufficient distance is maintained between the BMS board and the cell module, to prevent damaging of the BMS during adverse conditions of the battery pack.
[00043] Figure 3a exemplarily illustrates a perspective view of a metal mesh structure and battery pack casing, in accordance with an embodiment of the
15 present disclosure. Figure 3b exemplarily illustrates a detailed view of a metal mesh structure and battery pack casing as demarcated in Figure 3a, in accordance with an embodiment of the present disclosure. For brevity, Figure 3a and Figure 3b will be explained together. The metal mesh structure 300 is made of interlinked thin wire strands 302 which create a pre-defined pattern
20 304. The metal mesh structure is configured to structurally strengthen and support the casing 102. The pre-defined pattern 304 (as shown in Figure 3b) comprises a polygonal shaped interlinked pattern. The polygonal shape may be any one of a rectangle, a parallelogram, an octagonal, a circle, or the like. The polygonal shape may be determined based on the requirements of the
25 battery pack 100.

[00044] Figure 4a exemplarily illustrates a perspective side view of a metal mesh structure and battery pack casing, in accordance with an embodiment of the present disclosure. Figure 4b exemplarily illustrates a detailed side view of a metal mesh structure and battery pack casing as demarcated in
30 Figure 4a, in accordance with an embodiment of the present disclosure. For brevity, Figure 4a and Figure 4b will be explained together. During the

casting of the casing 102 the metal mesh structure 300 is inserted in a die used for the casting of the casing 102. The metal mesh structure 300 is configured to be sandwichedly disposed between layers of an alloy material used for casting of the casing 102. The alloy material is configured to form a matrix
5 structure and occupy spaces present in the interlinked thin wire strands 302 of the metal mesh structure 300 thereby forming a solid structure for the casing 102. The metal mesh structure 300 is made of steel which enables absorption of mechanical shock and increases the rigidity of the casing of the battery pack 100. In an embodiment, one or more such metal mesh structures
10 may be inserted during the casting of the casing 102, further increasing the rigidity as per the requirement.
[00045] As per an embodiment, the interlinked thin wire strands 302 are of uniform cross-sectional area, providing uniform strength across all regions of the casing 102, and decreasing the complexity of manufacturing of the metal
15 mesh structure 300. As per another embodiment, the interlinked thin wire strands 302 are of varying cross-sectional area in one or more pre-defined regions of the casing 102. These pre-defined regions of the casing are regions that are fracture-prone and exposed to maximum impact during adverse conditions. The interlinked thin wire strands 302 are of greater cross-sectional
20 area in the fracture-prone regions of the casing 102, thereby optimising the structure integrity of the casing 102. The casing 102 is made of an alloy material comprising at least one of ADC12, or ADC6. The casing 102 may also be manufactured using alloy materials generally known in the art.
[00046] A person with ordinary skills in the art will appreciate that the
25 systems, modules, and sub-modules have been illustrated and explained to serve as examples and should not be considered limiting in any manner. It will be further appreciated that 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.
[00047] The present claimed invention solves the technical problem of providing a rigid and sturdy battery pack casing, which is fire resistant and

prevents thermal runaway by aiding dissipation of heat into the environment. The dissipation of heat reduces the probability of thermal runaway, which consequently decreases the probability of explosion of the battery pack. The present subject matter also provides a battery pack with casing that is capable of absorbing extreme mechanical shocks that the casing could encounter during explosions, accidental impacts or during thermal runaway conditions.
[00048] The present subject matter also advantageously enables effective sealing between the joints of the casing, which further strengthens the casing of the battery pack. This also increases the tolerance of the battery pack in case of rough handling, by providing a structurally stronger batter pack than
5 conventionally manufactured battery packs. The present subject matter also provides better thermal conductivity, thus, preventing the effect of thermal runaway and ensure quicker cooling of the battery.
[00049] In view of the above, the claimed limitations as discussed above are not routine, conventional, or well understood in the art, as the claimed
10 limitations enable the above solutions to the existing problems in conventional technologies.
[00050] The present subject matter is described using a battery pack, whereas the claimed subject matter can be used in any other type of application employing above-mentioned battery pack assembly configuration, with
15 required changes and without deviating from the scope of invention. Further, it is intended that the disclosure and examples given herein be considered as exemplary only.
[00051] The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some
20 embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the invention(s)” unless expressly specified otherwise. The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise. The terms “a”, “an” and “the” mean “one or more”, unless expressly specified
25 otherwise.

[00052] 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
5 detailed description, but rather by any claims that issue on an application based here on. Accordingly, the 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.
[00053] While various aspects and embodiments have been disclosed herein,
10 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 not intended to be limiting, with the true scope and spirit being indicated by the following claims.
[00054] A person with ordinary skills in the art will appreciate that the
15 systems, modules, and sub-modules have been illustrated and explained to serve as examples and should not be considered limiting in any manner. It will be further appreciated that 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.
20 [00055] 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
25 of suitable processes and system modules, and are not limited to any particular computer hardware, software, middleware, firmware, microcode, and the like. The claims can encompass embodiments for hardware and software, or a combination thereof.
[00056] While the present disclosure has been described with reference to
30 certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without

departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. Therefore, it is intended that the present disclosure not be limited to the
5 particular embodiment disclosed, but that the present disclosure will include all embodiments falling within the scope of the appended claims.

Reference Numerals: 100 – Battery Pack 102 – Casing
102a – Top casing

5 102b – Side casing

102c – Bottom casing 104 – Cell module
106 – Plurality of cells
202 – Battery Management System
10 204 – One or more studs 206 – Base member
300 – Metal mesh structure
302 - Interlinked thin wire strands
304 - Polygonal shaped interlinked pattern
, Claims:We claim:
1. A battery pack (100), the battery pack (100) comprising:
a casing (102) configured to house a plurality of cells (106) (106), wherein the casing (102) being integrally reinforced using a metal mesh structure (300),
wherein the metal mesh structure (300) being made by interlinked thin wire strands (302) configured to create a pre- defined pattern, and
wherein the metal mesh structure (300) being configured to structurally strengthen and support the casing (102).
2. The battery pack (100) as claimed in claim 1, wherein the casing (102) comprises at least one of a top casing (102a), a bottom casing (102c), and a side casing (102b), wherein at least one of the top casing (102a), the bottom casing (102c), and the side casing (102b) comprises the metal mesh structure (300).
3. The battery pack (100) as claimed in claim 1, wherein the plurality of cells (106) forming a cell module (104) being accommodated inside a cavity defined within the casing (102).
4. The battery pack (100) as claimed in claim 1, wherein during casting of the casing (102) the metal mesh structure (300) is inserted in a die used for the casting of the casing (102), wherein the metal mesh structure (300) being configured to be sandwichedly disposed between layers of an alloy material used for casting of the casing (102), wherein the alloy material being configured to form a matrix structure and occupy spaces present in the interlinked thin wire strands
(302) of the metal mesh structure (300) thereby forming a solid structure for the casing (102).
5. The battery pack (100) as claimed in claim 1, wherein the metal mesh structure (300) being made of steel and configured to absorb mechanical shock and increase the rigidity of the casing (102) of the battery pack (100).

6. The battery pack (100) as claimed in claim 1, wherein the interlinked thin wire strands (302) are of uniform cross-sectional area.
7. The battery pack (100) as claimed in claim 1, wherein the interlinked thin wire strands (302) are of varying cross-sectional area in one or more pre-defined regions of the casing (102).
8. The battery pack (100) as claimed in claim 1, wherein the casing (102) being made of an alloy material comprising at least one of ADC12, or ADC6.
9. The battery pack (100) as claimed in claim 1, wherein the metal mesh structure (300) is manufactured using at least one of a casting process, a forming process, or a combination thereof.
10. The battery pack (100) as claimed in claim 1, wherein the pre-defined pattern comprises a polygonal shaped interlinked pattern (304).
11. The battery pack (100) as claimed in claim 1, wherein the battery pack
(100) comprises a Battery Management System (BMS) (202), wherein the BMS (202) is mounted on the cell module (104) using one or more studs (204).