Description:TECHNICAL FIELD
[0001] The present subject matter relates to a battery pack. More particularly, the present subject matter relates to a busbar assembly for the battery pack.

BACKGROUND
[0002] Advancement of technology has illustrated a dire dependency on electrical energy for operation of various electrical and electronic equipment as well as development of vehicles employing electrical energy. The massive utility that electrical energy presents, puts a concomitant pressure on the development of electrical energy storage devices or system to help realize the utility of electrical energy. The developed electrical energy storage systems are mandatorily equipped with safety mechanisms to cope in an event of malfunctioning of the electrical energy storage systems.
[0003] Further, recently there has been tremendous research and development occurring in the field of mobility with reference to electric and plug-in hybrid vehicles. The demands in the field of electric mobility mandate a requirement of effective monitoring and diagnosis of thermal runaway, short circuiting, and other forms of electrical malfunctioning of the energy storage system. Further, the energy storage systems used in mobility are configured to be rechargeable in pursuit of re-use.
[0004] An energy storage system typically includes a battery pack comprising of a plurality of cells or a plurality of battery modules configured to store electrical energy and supply the stored electrical energy to an external load. The external load draws the electrical energy from the battery pack in continuance of its regular operation.
[0005] Conventionally, lithium-ion (hereinafter referred to as Li-ion) batteries have been a popular choice in the battery packs owing to their high energy density, high power density, excellent cycle performance, and environmental friendliness. The apprehension in usage of Li-ion cells is the uncontrolled exothermic reaction occurring in thermal runaway of Li-ion cells are fast, violent, and self-accelerating. Typically, in thermal runaway there is an accelerated release of heat from the cell due to uncontrolled exothermic reaction where the cell losses the ability to dissipate the heat as quickly as the heat is generated in the cell, ultimately leading to loss of thermal stability of the cell. The heat generated during thermal runaway may propagate to neighbouring cell as well as neighbouring electrical and electronic equipment leading to catastrophic failure. In order to ensure safe operation of the battery packs, the manufacturer has to ensure that the battery packs having parallel cell connections is equipped with a circuit which enables isolation of faulty cells and eliminate the circulating currents.
[0006] Conventionally, the battery packs and other forms of electrical energy storage devices and systems are equipped with a battery management system (hereinafter referred to as BMS). The BMS monitors the health of the battery pack through one or more battery parameters such as voltage, charging current, temperature, and state of charge of the battery cells. The BMS upon detection of discrepancies in the one or more battery parameters cuts-off the functioning of the entire battery pack for coping with the possibility of malfunctioning of the battery which may lead to thermal runaway. The disadvantage of the inclusion of the BMS in coping with individually malfunctioning cells is that the BMS cuts-off the entire functionality of the battery pack yielding complete halt of the battery operations which attenuate associated cost, time, and labour.
[0007] Conventionally, the battery packs and other forms of electrical energy storage devices and systems are equipped with additional electrical fuses. The additional electrical fuses connected to a printed circuit board (hereinafter referred to as PCBs) in connection with the battery pack to isolate the malfunctioning battery pack. However, the disclosed configuration known in the art results in an excessive increase in the number of components associated with the battery pack and the corresponding weight and size of the battery pack. Further, addition of extra components such as electrical fuses connected to PCBs increases the manufacturing and assembly time of the battery pack as well as the cost associated with the battery pack. The configuration of the known art further apprehensively impacts the serviceability, maintainability, and accessibility of the components of the battery pack as already known in the prior art.
[0008] Further, it is known in a prior art to equip the battery pack with additional electronic components configured to isolate an individual malfunctioning cell allowing the other cells of the battery pack continue its normal functioning. The drawback of additional electronic components in the battery pack increases the overall weight, associated cost, and number of components of the battery pack. In automobile industries, mobility demands a high power to weight ratio which makes lighter batteries more desirable to achieve improved vehicle performance.
[0009]
[00010] 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.
[00011] The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[00012] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[00013] Figure 1. illustrates a side perspective view of a battery pack, in accordance with embodiments of the present disclosure.
[00014] Figure 2. illustrates an exploded view of the battery pack, in accordance with embodiments of the present disclosure.
[00015] Figure 2(a) illustrates a top view of a busbar assembly of the battery pack, in accordance with embodiments of the present disclosure.
[00016] Figure 2(b) illustrates a side perspective view of the busbar assembly of the battery pack, in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

[00017] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. According to an embodiment, a busbar for a battery pack. As per an embodiment, such battery pack can be used for automotive or non-automotive application. Further "front" and "rear", and "left" and "right" referred to in the ensuing description of the illustrated embodiment refer to front and rear and left and right directions as seen from a rear portion of the battery pack and looking forward. Furthermore, a longitudinal axis (L-L’) unless otherwise mentioned, refers to a front to rear axis relative to the battery pack, while a lateral axis (C-C’) unless otherwise mentioned, refers generally to a side to side, or left to right axis relative to the battery pack.
[00018] However, it is contemplated that the disclosure in the present invention may be applied to non-automotive application without defeating the spirit of the present subject matter. The detailed explanation of the constitution of parts other than the present invention which constitutes an essential part has been omitted at suitable places.
[00019] Therefore, it is an object of the present subject matter to provide a battery pack with multiple fusing regions configured to isolate malfunctioning cells from the battery pack circuit to ensure normal functioning of the battery pack and alleviate occurrences of thermal runaway in the battery pack.
[00020] To this end, the present subject matter discloses a busbar assembly comprising a first busbar. The first busbar includes a first portion, a second portion, one or more fusing regions; and one or more connecting portions. The said connecting portions being configured to connect with one or more cells. The one or more said fusing regions being selectively provided between one or more said connecting portions.
[00021] As per an embodiment, one or more said fusing regions being disposed between a first portion and a second portion of said busbar assembly.
[00022] As per another embodiment, said first portion includes a first set of cells 102A, and the second portion includes a second set of cells.
[00023] As per yet another embodiment, said first set of cells being selectively electrically connected in parallel or series to each other.
[00024] As per an embodiment, second set of cells being selectively electrically connected in parallel or in series to each other.
[00025] As per another embodiment, at least one of said first set of cells and at least one of said second set of cells are connected in series to each other.
[00026] As per yet another embodiment, at least one of said first set of cells and at least one of said second set of cells are connected in parallel to each other.
[00027] As per another embodiment, material of one or more said fusing region being different from that of remaining material of one or more said connecting portions.
[00028] As per an embodiment, the material of one or more said fusing region, being same as that of the remaining material of one or more said first busbar.
[00029] As per another embodiment, the material being made of two or more distinct metals or alloys with different properties, wherein the two or more distinct metals or alloys being metallurgically bonded together.
[00030] As per yet another embodiment, the material being made from a combination of aluminum, nickel, and copper.
[00031] As per another embodiment, the one or more first busbars being made from one of a nickel or copper.
[00032] As per another embodiment, one or more said first busbars has a plurality of first set of openings, said first set of openings being configured to receive one or more connecting portions.
[00033] As per yet another embodiment, the connecting portion has a plurality of second openings, wherein the plurality of second openings enables spot welding of the connecting portions to at least one of a positive terminal or a negative terminal of the one or more cells.
[00034] As per an embodiment, the geometric parameters of one of said fusing regions is lesser than one of said connecting portions.
[00035] As per yet another embodiment, one or more said fusing regions being configured to act as a fusing element when a current passing through the fusing region exceeds a pre-defined current.
[00036] As per another embodiment, wherein resistance of one of said first portion and said second portion of said busbar assembly is higher than resistance of one or more said fusing regions as width of one or more said fusing region being less than one of said one or more said first portion and second portion.
[00037] As per an aspect of the present invention a battery pack comprising one or more cells, and a busbar assembly. Each of one or more said cells being connected to form one or more modules. One or more cells being connected using said busbar assembly. The busbar assembly includes one or more first busbar(s). The first busbar(s) being configured to have one or more connecting portions, one or more second busbar(s). The one or more second busbar being configured to collect power from the battery pack. The one or more first busbars include one or more fusing regions. The fusing regions being provided between one or more connecting portions of one or more said first busbars.
[00038] 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.
[00039] Figure 1(a) exemplarily illustrates a side perspective view of a battery pack 100, in accordance with embodiments of the present disclosure. Figure 1(b) illustrates a side perspective exploded view of the battery pack 100, in accordance with embodiments of the present disclosure. Figure 1(a) and Figure 1(b) shall be discussed together.
[00040] With reference to Figure 1(b), 100 denotes a battery pack, 102 denotes one or more cells, 104 denotes busbar assembly, said busbar assembly 104 includes one or more first busbars 106 and one or more second busbars 107.
[00041] In an embodiment, the battery pack 100 comprises of one or more cells 102. The one or more cells 102 are connected by one or more first busbars 106. Each of the one or more first busbars 106 secures an electrical connection between adjacent cells of the battery pack 100 by connecting cell terminals and then giving it to one or more second busbars 107.
[00042] In an embodiment, the battery pack 100 disclosed in relation to the present subject matter includes any electrical energy storage device or system configured to store electrical energy and may include an energy storage pack, one or more battery cells, a plurality of battery modules and other forms of electrical energy storage equipment. The battery pack 100 is rechargeable and is configured to have a charged and discharged state. In a charged state of the battery pack 100, the battery pack 100 supplies the stored electrical energy to an external electrical load, an electrical or electronic equipment, electric or hybrid vehicle as and when required.
[00043] In an aspect of the present invention, the battery pack 100 comprises of a the one or more cells 102. The one or more cells 102 of the battery pack 100 are electrically connected either in series configuration or parallel configuration based on the intended use of the battery pack 100.
[00044] In an aspect of the present invention, the connection of the one or more cells 102 in series or parallel is based on the sector in which the battery pack 100 is utilised, and the energy demands of the external electrical load, electrical or electronic equipment or the electric vehicle. The difference in series configuration and parallel configuration of the one or more cells 102 is the impact the same holds on the output voltage of the battery pack 100 and the capacity of the battery pack 100.
[00045] In an embodiment, the battery pack 100 disclosed in accordance with the present disclosure comprises of the one or more cells 102 electrically connected in parallel configuration.
[00046] In an aspect of the present invention, the one or more cells 102 of the battery pack 100 are connected in a parallel configuration when the current flowing through the battery pack 100 is to be distributed in the entire battery pack 100.
[00047] Figure 2(a) exemplarily illustrates a top view of the busbar of the battery pack, in accordance with embodiments of the present disclosure. Figure 2(b) illustrates a side perspective view of the busbar of the battery pack, in accordance with embodiments of the present disclosure. Figure 2(a) and Figure 2(b) shall be discussed together. In an embodiment, the one or more cells 102 is connected using one or more first busbars 106 to ensure electrical connectivity between the one or more cells 102 and carry current in the circuit of the battery pack 100.
[00048] In an aspect of the present invention, the one or more first busbars 106 are composed of a material. The material used for composition of the one or more first busbars 106 is selected from at least one of or a combination of aluminium, nickel, and copper. The material used for one or more first busbars 106 should allow electrical connectivity between the one or more cells 102 in the battery pack 100.
[00049] The first busbar includes a first portion 104a and a second portion 104b. The first portion 104a further includes a first set of cells 102a, and the second portion 104b includes a second set of cells 102b.
[00050] In an aspect of the present invention, the battery pack 100 comprises a plurality of battery modules and each battery modules comprises of one or more battery cells 102. The one or more first busbars 106 connect the one or more cells 102 as well as the plurality of battery modules either in series configuration or parallel configuration.
[00051] In an embodiment, the cell terminals of adjacent cells of the one or more cells 102 are connected to each other using the one or more first busbars 106. The first busbar 106 being configured to have one or more first set of openings 106a. The openings 106a being configured to receive one or more connecting portions 108. The connecting portions 108 of one or more first busbars 106 are spot welded on each cell terminal of the one or more cells 102. The one or more first busbars 106 carry electric current between adjacent cells of the one or more cells 102 in the battery pack 100.
[00052] In an embodiment, each of the one or more first busbars 106 comprises of one or more fusing regions 109. The one or more fusing regions 109 having lesser width as compared to one or more connecting portions 108.
[00053] In an embodiment, one of said one or more fusing regions 109 being provided the first portion 104a and a second portion 104b of the first busbar 106.
[00054] In an aspect of the present invention, the one or more fusing regions 109, are configured to act as fusing elements which blow-off in the event of current through a cell exceeds a pre-defined current. In the event of a cell malfunctioning, the current through the one or more cells 102 are typically dumped on the malfunctioning cell leading to higher currents in the malfunctioning cell which exceed the pre-defined current value.
[00055] In an aspect of the present invention, the one or more fusing regions 109 being provided between the connecting portions 108. The fusing regions 109 connects a first portion 104a of the first busbar 106 to a second portion 104b of the first busbar 106.
[00056] In an embodiment, the connecting portion 108 is composed of a material which is different from the remaining material used for composing the first busbar 106.
[00057] In an aspect of the present invention, the two or more distinct metals or alloys used for composing the material are metallurgically bonded together to achieve the functional benefits which are otherwise deemed unachievable by a single metal.
[00058] In an embodiment, each first busbar 106 comprises of the connecting portions 108 having a plurality of second openings 108a where the plurality of second openings 108a enables spot welding of the connecting portion 108 of the first busbar 106 to at least one of a positive terminal of the cells the first busbar 106 connects.
[00059] In an embodiment, each first busbar 106 comprises of the connecting portion 108 having a plurality of second openings 108a where the plurality of second openings 108a enables spot welding of the connecting portion 108 of the first busbar 106 to at least one of a negative terminal of the cells the first busbar 106 connects.
[00060] In an embodiment, one or more of said fusing regions 109 being offset to a centre line of a weld zone. Further, the fusing region 109 can be on the extreme ends of one or more first busbars 106.
[00061] In an aspect of the present invention, each first busbar 106 of the one or more first busbars 106 comprises of one or more fusing region 109, configured to act as fusing elements. The fusing region 109 is configured to blow-off in the event of current in the battery pack 100 exceeding a pre-defined current.
[00062] For example, the pre-defined current for the purpose of fusing in the fusing region 109, of the first busbar 106 is 10 A and there are 5 cells of the plurality of cells 102 connected in parallel and configured to carry a maximum of 8A of current. In the unfortunate event of an electrical mishap where one cell behaves abnormally or is deemed to malfunction, the electric current flowing through the one or more cells 102 is dumped on the malfunctioning cell. The fusing region 109, of the first busbar 106 having necks formed carries the current flowing through the one or more cells 102. The current passing through the first busbar 106 is sensed by one of the fusing regions 109, and when the current passing through the first busbar 106 exceeds 10A, the heat generated due to the high current is transmitted to the fusing region 109. In the event of the current passing through the fusing region 109, of the first busbar 106 exceeding 10A, the fusing region 109, would blow out due to the transmitted heat, disconnecting or isolating the malfunctioning cell from the one or more cells 102. Thus, the disclosed configuration achieves isolation of the malfunctioning cell from the remaining cells of the battery pack 100 circuit by employing a battery pack 100 provided with multiple fusing.
[00063] The claimed invention in an aspect provides enhanced safety and security in the operating environment of the battery pack 100. In an embodiment, the busbars 106 comprises of one or more fusing regions being configured to act as fusing element which blow-off once the current passing through the busbars exceeds a pre-defined current resulting in isolation of the malfunctioning cell from the one or more cells, alleviate occurrences of thermal runaway and enable normal functioning of the other cells of the battery pack. The disclosed configuration in turn saves money, time and energy by allowing normal functioning of the battery pack after isolating the malfunctioning cell.
[00064] Conventional battery packs employing BMS fail to isolate the malfunctioning cell from the other cells of the battery pack which results in halting of the operation of the battery pack. The present subject matter addresses this exact drawback through the disclosed configuration of multiple fusing regions of the busbars.
[00065] In an aspect, the disclosed configuration of the battery pack does not require the involvement of additional semiconductor components to isolate the malfunctioning cell by forming plurality of fusing regions in the busbars itself. Consequently, the disclosed configuration does not affect the overall weight, size, number of components, and cost of the battery pack.
[00066] Further, in accordance with the present disclosure, the disclosed configuration enhances accessibility, serviceability, and maintenance of the battery pack. Additionally, the disclosed configuration allows adaptability of the busbar’s configuration in conventional battery pack without any significant deviations or revamping of the core manufacturing process. The flexibility of manufacturing variants accorded as per the present disclosure allows battery pack variants in forms of size of the battery pack, range of power supply and capacity of the battery pack.
[00067] To this extent, the reduced weight of the battery pack achieved in accordance with the present disclosure provides a high power to weight ratio in the vehicle where the battery pack is employed, ultimately yielding improved vehicle performance.
[00068] Further, the present disclosure of the battery pack achieves active paralleling circuits in the battery pack where the plurality of cells are connected in parallel configuration.
[00069] In light of the abovementioned advantages and the technical advancements provided by the disclosed method and system, the claimed steps as discussed above are not routine, conventional, or well understood in the art, as the claimed steps enable the following solutions to the existing problems in conventional technologies. Further, the claimed steps clearly bring an improvement in the functioning of the device itself as the claimed steps provide a technical solution to a technical problem.
[00070] The above-mentioned example is only provided in pursuit of clarity, illustration and elucidation purposes of the present subject matter and shall not be construed to limit the scope of the present subject matter to abovementioned aspects of the invention.
[00071] Furthermore, the battery pack as per preferred embodiment is applicable for non-automotive application. Further, it includes application for multi-wheeled vehicles like three, or four wheeled vehicles as it will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention.

List of reference numerals:
100 Battery pack
101 Busbar assembly
102 Cells
102A First set of cells
102B Second set of cells
103 Second busbar
104 Busbar assembly
104A First portion
104B Second portion
106 First busbar
106a First set of openings
107 Second busbar
108 Connecting portions
108a Second openings
109 Fusing regions
, Claims:We Claim:
1. A busbar assembly 104 comprising,
a first busbar 106, said first busbar 106 includes
a first portion 104a;
a second portion 104b;
one or more fusing regions 109; and
one or more connecting portions 108, one or more said connecting portions 108 being configured to connect with one or more cells 102,
wherein one or more said fusing regions 109 being selectively provided between one or more said connecting portions 108.
2. The busbar assembly 104 as claimed in claim 1, wherein one or more said fusing regions 109 being disposed between a first portion 104A and a second portion 104B of said busbar assembly 104.
3. The busbar assembly 104 as claimed in claim 1, wherein said first portion 104A includes a first set of cells 102A, and the second portion 104B includes a second set of cells 102B.
4. The busbar assembly 104 as claimed in claim 3, wherein said first set of cells 102A being selectively electrically connected in parallel or series to each other.
5. The busbar assembly 104 as claimed in claim 3, wherein said second set of cells 102B being selectively electrically connected in parallel or in series to each other.
6. The busbar assembly 104 as claimed in claim 3, wherein at least one of said first set of cells 102A and at least one of said second set of cells 102B are connected in series to each other.
7. The busbar assembly 104 as claimed in claim 3, wherein at least one of said first set of cells 102A and at least one of said second set of cells 102B are connected in parallel to each other.
8. The busbar assembly 104 as claimed in claim 1, wherein material of one or more said fusing region 109 being different from that of remaining material of one or more said connecting portions 108.
9. The busbar assembly 104 as claimed in claim 1, wherein the material of one or more said fusing region 109, being same as that of the remaining material of one or more said first busbar 106.
10. The busbar assembly 104 as claimed in claim 9, wherein the material being made of two or more distinct metals or alloys with different properties, wherein the two or more distinct metals or alloys being metallurgically bonded together.
11. The busbar assembly 104 as claimed in claim 9, wherein the material being made from a combination of aluminum, nickel, and copper.
12. The busbar assembly 104 as claimed in claim 1, wherein the one or more first busbars 106 being made from one of a nickel or copper.
13. The busbar assembly 104 as claimed in claim 1, wherein one or more said first busbars 106 has a plurality of first set of openings 106a, said first set of openings 106a being configured to receive one or more connecting portions 108.
14. The busbar assembly 104 as claimed in claim 1, wherein the connecting portions 108 has a plurality of second openings 108a, wherein the plurality of second openings 108a enables spot welding of the connecting portions 108a to at least one of a positive terminal or a negative terminal of the one or more cells 102.
15. The busbar assembly 104 as claimed in claim 1, wherein the geometric parameters of one of said fusing regions 109 is lesser than one of said connecting portions 108a.
16. The busbar assembly 104 as claimed in claim 1, wherein one or more said fusing regions 109 being configured to act as a fusing element when a current passing through the fusing region 109 exceeds a pre-defined current.
17. The busbar assembly 104 as claimed in claim 1, wherein resistance of one of said first portion 104A and said second portion 104B of said busbar assembly 104 is higher than resistance of one or more said fusing regions 109 as width of one or more said fusing region 109 being less than one of said one or more said first portion 104A and second portion 104B.
18. The busbar assembly 104 as claimed in claim 1, wherein one or more said fusing regions 109 being offset to a centre line of a weld zone.
19. A battery pack 100 comprising:
one or more cells 102, each of one or more said cells 102 being connected to form one or more modules;
a busbar assembly 104, the one or more cells 102 being connected using said busbar assembly 104, said busbar assembly 104 includes:
one or more first busbar(s) 106, said first busbar(s) 106 being configured to have one or more connecting portions 108;
one or more second busbar(s) 103, the one or more second busbar 103 being configured to collect power from the battery pack 100;
wherein the one or more first busbars 106 include one or more fusing regions 109; and
wherein said fusing regions 109 being provided between one or more connecting portions 108 of one or more said first busbars 106.