Description:FIELD OF THE INVENTION
Embodiments of a present disclosure relate to electrical circuit protective fuses and more particularly to implementation of electrical fuse for each battery cell along with interconnector cells in battery packs.

BACKGROUND OF THE INVENTION:
Electric Vehicles may contain an energy storage device, such as a battery pack, to act as a propulsion source for the vehicle. The battery pack may include components and systems to assist in managing vehicle performance and operations. The battery pack may include one or more arrays of battery cells interconnected electrically between battery cell terminals and interconnector busbars. The battery pack and surrounding environment may include a thermal management system to assist in managing temperature of the battery pack components, systems, and individual battery cells.

In order to meet such demands in electric vehicles, lithium-ion battery cells are preferred. The battery pack consists of numerous modules linked to a Battery Management System (BMS) and a cooling system that regulate and manage the temperature, voltage, and other parameters of the battery pack. BMS is a technology developed to monitor various parameters of the battery packs in electric vehicles. However, to protect these battery cells, a secure link is required between the cell stack in the battery pack and the BMS board. The BMS board comprises of bus bars linked to semiconductor devices known as metal oxide semiconductor field effect transistors (MOSFET).

It is highly required to protect the battery pack from the high voltage and short circuits. In electric vehicles, it is obvious to see the motor failure or load fault. In the case of high voltage which in turn causes a short circuit, could lead to damaging the entire battery pack causing fire and danger. Therefore, it is important to isolate the faulty battery cell and prevent propagation of fire to the entire battery pack.

PROBLEM TO BE SOLVED BY INVENTION
In the conventional electrical fuses, they are not reliable in operating at higher voltage and they are quite limited in their functionality. They are of big size and require more space in the battery pack.

Hence, it is a primary objective of the current invention to implement a reliable electrical fuse to operate at higher voltage and of smaller sizes that are compact, which occupy lesser space in the battery pack.

Often electric vehicles report motor failure or load fault when high current passes from battery pack. In such situation, BMS opens the pack level fuse to isolate the battery pack. However, in some cases the pack level fuse become inefficient in isolating the battery pack leading to dangerous thermal runaways.

Thus, it is another objective of the current invention to provide additional security to the battery pack to avoid thermal runaways.

The above-mentioned shortcomings, disadvantages and problems are addressed herein, and which will be understood by reading and studying the following specification.

SUMMARY OF THE INVENTION
Various embodiments herein describe a system involved to isolate faulty battery cell in a battery pack. The system comprises of the following. One or more battery cells are electrically connected to a thermo-electric conductor through one or more interconnect tabs. The one or more interconnect tabs operably coupled to a copper layer of the thermo-electric conductor, wherein the one or more interconnect tabs are configured to connect with the corresponding one or more battery cells. One or more through-holes of the thermo-electric conductor configured to facilitate welding of the one or more interconnect tabs to the corresponding one or more battery cells using the at least one welding method. One or more cell level fusible links on the thermo-electric conductor are allocated for each of the one or more battery cells, where the one or more cell level fusible links allow the current to pass between the one or more battery cells and the copper layer of the thermo-electric conductor, characterized in that, the one or more cell level fusible links are created by strategically etching a certain portion of the copper layer of the thermo-electric conductor at one or more regions for each of the one or more battery cells, where the cell level fusible link blows off to isolate the one or more faulty battery cells from the other battery cells when high current is transmitted through the cell level fusible link of the one or more faulty battery cells.

According to an embodiment of the present invention, representation of a thermo-electric conductor is disclosed. The one or more cell level fusible links are created by strategically etching a certain portion of the copper layer of the thermo-electric conductor at one or more regions for each of the one or more battery cells, where the cell level fusible link blows off to isolate the one or more faulty battery cells from the other battery cells when high current is transmitted through the cell level fusible link of the one or more faulty battery cells. The thermo-electric conductor may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.

According to an embodiment of the present invention, representation of a section of a battery pack is disclosed. The one or more battery cells are electrically connected to a thermo-electric conductor through one or more interconnect tabs. The one or more interconnect tabs operably coupled to a copper layer of the thermo-electric conductor, wherein the one or more interconnect tabs are configured to connect with the corresponding one or more battery cells.

As per first embodiment of the current invention, the thermo-electric conductor may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.

As per second embodiment of the current invention, the high current is above 50 Ampere for 21700 form factor lithium-ion battery cell resulting from a fault at the battery cell, a load or a motor controller.

As per third embodiment of the current invention, the one or more faulty battery cells may be due to overheating, internal short-circuit, over charging, over discharging, mechanical abuse.

As per fourth embodiment of the current invention, the cell level fusible link is of a predetermined length, width and thickness which is capable of carrying functional current and is configured to blow off when high current flows through it.

As per fifth embodiment of the current invention, the cell level fusible link blows off upon failure of a pack level fuse to blow during the load fault, still further the duration taken by the cell level fusible link is higher than the duration taken by the pack level fuse to blow off during the load fault. A switch is a device that enables or disables passing of current between the load and the battery pack.

As per another embodiment of the invention, a method to isolate one or more faulty battery cells in a battery pack is disclosed. The method comprises of the following. Connecting one or more battery cells electrically to a thermo-electric conductor through one or more interconnect tabs. Coupling the one or more interconnect tabs operably to a copper layer of the thermo-electric conductor, wherein the one or more interconnect tabs are configured to connect with the corresponding one or more battery cells. Configuring one or more through-holes of the thermo-electric conductor to facilitate welding of the one or more interconnect tabs to the corresponding one or more battery cells using the at least one welding method. Allocating one or more cell level fusible links on the thermo-electric conductor for each of the one or more battery cells, where the one or more cell level fusible links allow the current to pass between the one or more battery cells and the copper layer of the thermo-electric conductor, characterized in that, creating the one or more cell level fusible links by strategically etching a certain portion of the copper layer of the thermo-electric conductor at one or more regions for each of the one or more battery cells, where the cell level fusible link blows off to isolate the one or more faulty battery cells from the other battery cells when high current is transmitted through the cell level fusible link of the one or more faulty battery cells.

The foregoing has outlined, in general, the various aspects of the invention and serves as an aid to better understanding the more complete detailed description which is to follow. In reference to such, there is to be a clear understanding that the present invention is not limited to the method or application of use described and illustrated herein. It is intended that any other advantages and objects of the present invention that become apparent or obvious from the detailed description or illustrations contained herein are within the scope of the present invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The other objects, features and advantages will occur to those skilled-in-the-art from the following description of the preferred embodiments and the accompanying drawings in which:

Figure 1 is a schematic block diagram illustrating a system involved to isolate faulty battery cell in a battery pack (101), according to an embodiment of the present invention.

Figure 2 is a schematic diagram representing a thermo-electric conductor (106), according to an embodiment of the present invention.

Figure 3 is a schematic diagram representing a section of a battery pack (101), according to an embodiment of the present invention.

Further, those skilled-in-the-art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a system and method to isolate faulty battery cell in a battery pack. In the following detailed description of the embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled-in-the-art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

The specification may refer to “an”, “one” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” 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 and arrangements of one or more of the associated listed items.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Embodiments of the present invention will be described below in detail with reference to the accompanying figures.

As per Figure 1, a system involved to isolate faulty battery cell in a battery pack (101) is disclosed. The system comprises of the following. One or more battery cells (104) are electrically connected to a thermo-electric conductor (106) through one or more interconnect tabs (107). The one or more interconnect tabs (107) operably coupled to a copper layer of the thermo-electric conductor (106), wherein the one or more interconnect tabs (107) are configured to connect with the corresponding one or more battery cells (104). One or more through-holes (108) of the thermo-electric conductor (106) configured to facilitate welding of the one or more interconnect tabs (107) to the corresponding one or more battery cells (104) using the at least one welding method. A battery management system (BMS) (102) is configured to monitor one or more battery cells (104) of the battery pack (101). One or more cell level fusible links (109) on the thermo-electric conductor (106) are allocated for each of the one or more battery cells (104), where the one or more cell level fusible links (109) allow the current to pass between the one or more battery cells (104) and the copper layer of the thermo-electric conductor (106), characterized in that, the one or more cell level fusible links (109) are created by strategically etching a certain portion of the copper layer of the thermo-electric conductor (106) at one or more regions for each of the one or more battery cells (104), where the cell level fusible link (109) blows off to isolate the one or more faulty battery cells (105) from the other battery cells (104) when high current is transmitted through the cell level fusible link (109) of the one or more faulty battery cells (105).

As per Figure 2, representation of a thermo-electric conductor (106) is disclosed. The one or more cell level fusible links (109) are created by strategically etching a certain portion of the copper layer of the thermo-electric conductor (106) at one or more regions for each of the one or more battery cells (104), where the cell level fusible link (109) blows off to isolate the one or more faulty battery cells (105) from the other battery cells (104) when high current is transmitted through the cell level fusible link (109) of the one or more faulty battery cells (105). The thermo-electric conductor (106) may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.

As per Figure 3, representation of a section of a battery pack (101) is disclosed. The one or more battery cells (104) are electrically connected to a thermo-electric conductor (106) through one or more interconnect tabs (107). The one or more interconnect tabs (107) operably coupled to a copper layer of the thermo-electric conductor (106), wherein the one or more interconnect tabs (107) are configured to connect with the corresponding one or more battery cells (104).

As per first embodiment of the current invention, the thermo-electric conductor (106) may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.

As per second embodiment of the current invention, the high current is above 50 Ampere for 21700 form factor lithium-ion battery cell resulting from a fault at the battery cell, a load (110) or a motor controller (111).

As per third embodiment of the current invention, the one or more faulty battery cells (105) may be due to overheating, internal short-circuit, over charging, over discharging, mechanical abuse.

As per fourth embodiment of the current invention, the cell level fusible link (109) is of a predetermined length, width and thickness which is capable of carrying functional current and is configured to blow off when high current flows through it.

As per fifth embodiment of the current invention, the cell level fusible link (109) blows off upon failure of a pack level fuse (112) to blow during the load fault, still further the duration taken by the cell level fusible link (109) is higher than the duration taken by the pack level fuse (112) to blow off during the load fault. A switch (103) is a device that enables or disables passing of current between the load (110) and the battery pack (101).

As per another embodiment of the invention, a method to isolate one or more faulty battery cells (105) in a battery pack (101) is disclosed. The method comprises of the following. Connecting one or more battery cells (104) electrically to a thermo-electric conductor (106) through one or more interconnect tabs (107). Coupling the one or more interconnect tabs (107) operably to a copper layer of the thermo-electric conductor (106), wherein the one or more interconnect tabs (107) are configured to connect with the corresponding one or more battery cells (104). Configuring one or more through-holes (108) of the thermo-electric conductor (106) to facilitate welding of the one or more interconnect tabs (107) to the corresponding one or more battery cells (104) using the at least one welding method. Allocating one or more cell level fusible links (109) on the thermo-electric conductor (106) for each of the one or more battery cells (104), where the one or more cell level fusible links (109) allow the current to pass between the one or more battery cells (104) and the copper layer of the thermo-electric conductor (106), characterized in that, creating the one or more cell level fusible links (109) by strategically etching a certain portion of the copper layer of the thermo-electric conductor (106) at one or more regions for each of the one or more battery cells (104), where the cell level fusible link (109) blows off to isolate the one or more faulty battery cells (105) from the other battery cells (104) when high current is transmitted through the cell level fusible link (109) of the one or more faulty battery cells (105).

FURTHER ADVANTAGES OF THE INVENTION
The current invention provides a reliable electrical fuse to operate at higher voltage and of smaller sizes that are compact, which occupy lesser space in the battery pack. Also, additional security is provided to the battery pack to avoid thermal runaways.

Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims. It is also to be understood that the following claims are intended to cover all the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

REFERENCE TABLE

S.No. Name Numbering
1. a battery pack 101
2. a battery management system (BMS) 102
3. a switch 103
4. one or more battery cells 104
5. one or more faulty battery cells 105
6. a thermo-electric conductor 106
7. one or more interconnect tabs 107
8. one or more through-holes 108
9. one or more cell level fusible links 109
10. a load 110
11. a motor controller 111
12. a pack level fuse 112

, Claims:CLAIMS
We claim:

1. A system to isolate one or more faulty battery cells (105) in a battery pack (101), the system comprising:
one or more battery cells (104) are electrically connected to a thermo-electric conductor (106) through one or more interconnect tabs (107);
the one or more interconnect tabs (107) operably coupled to a copper layer of the thermo-electric conductor (106), wherein the one or more interconnect tabs (107) are configured to connect with the corresponding one or more battery cells (104);
one or more through-holes (108) of the thermo-electric conductor (106) configured to facilitate welding of the one or more interconnect tabs (107) to the corresponding one or more battery cells (104) using the at least one welding method;
one or more cell level fusible links (109) on the thermo-electric conductor (106) are allocated for each of the one or more battery cells (104), where the one or more cell level fusible links (109) allow the current to pass between the one or more battery cells (104) and the copper layer of the thermo-electric conductor (106),
characterized in that,
the one or more cell level fusible links (109) are created by strategically etching a certain portion of the copper layer of the thermo-electric conductor (106) at one or more regions for each of the one or more battery cells (104), where the cell level fusible link (109) blows off to isolate the one or more faulty battery cells (105) from the other battery cells (104) when high current is transmitted through the cell level fusible link (109) of the one or more faulty battery cells (105).

2. The system as claimed in claim 1, wherein the thermo-electric conductor (106) may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.

3. The system as claimed in claim 1, wherein the high current is above 50 Ampere for 21700 form factor lithium-ion battery cell resulting from a fault at the battery cell, a load (110) or a motor controller (111).

4. The system as claimed in claim 1, wherein the one or more faulty battery cells (105) may be due to overheating, internal short-circuit, over charging, over discharging, mechanical abuse.

5. The system as claimed in claim 1, wherein the cell level fusible link (109) is of a predetermined length, width and thickness which is capable of carrying functional current and is configured to blow off when high current flows through it.

6. The system as claimed in claim 1, wherein the cell level fusible link (109) blows off upon failure of a pack level fuse (112) to blow during the load fault, still further the duration taken by the cell level fusible link (109) is higher than the duration taken by the pack level fuse (112) to blow off during the load fault.

7. A method to isolate one or more faulty battery cells (105) in a battery pack (101), the method comprising:
connecting one or more battery cells (104) electrically to a thermo-electric conductor (106) through one or more interconnect tabs (107);
coupling the one or more interconnect tabs (107) operably to a copper layer of the thermo-electric conductor (106), wherein the one or more interconnect tabs (107) are configured to connect with the corresponding one or more battery cells (104);
configuring one or more through-holes (108) of the thermo-electric conductor (106) to facilitate welding of the one or more interconnect tabs (107) to the corresponding one or more battery cells (104) using the at least one welding method;
allocating one or more cell level fusible links (109) on the thermo-electric conductor (106) for each of the one or more battery cells (104), where the one or more cell level fusible links (109) allow the current to pass between the one or more battery cells (104) and the copper layer of the thermo-electric conductor (106),
characterized in that,
creating the one or more cell level fusible links (109) by strategically etching a certain portion of the copper layer of the thermo-electric conductor (106) at one or more regions for each of the one or more battery cells (104), where the cell level fusible link (109) blows off to isolate the one or more faulty battery cells (105) from the other battery cells (104) when high current is transmitted through the cell level fusible link (109) of the one or more faulty battery cells (105).