Description:FIELD OF THE INVENTION
Embodiments of a present disclosure relate to safety of a battery management system (BMS), and more particularly to lithium-ion battery cells.

BACKGROUND:
With increasing demand for scientific developments there is quite a demand for pollution-free vehicles for transportation purposes. To achieve this and cater the demands of the users in the automotive industry, electric vehicles are gaining popularity. In electric vehicles we generally use lithium-ion battery cells which are configured together and connected along with a battery management system (BMS) module. These battery cells are a source of power to electric vehicles and are subjected to various conditions. The BMS boards are configured to detect various parameters of a battery pack such as temperature, pressure, etc.

In the conventional battery systems, the users get reports with technical information and are alerted when there is fire hazard, which does not give sufficient time for the users to move away from the vehicle. Such alerts are provided with different types of sensors equipped along with additional hardware in the BMS Module. The location of placing additional sensors to detect the condition of the lithium-ion battery cells, when battery modules have inbuilt sensors, is considered as one of the design aspects in the industry. When lithium-ion battery cells are exposed to adverse heat conditions, internally the temperature goes up and chemical decomposition takes place resulting in emitting lot of gases thereby increasing pressure in the battery cell. In certain cases, due to high pressure in the battery cell, disc ruptures releasing all the gases from the battery cell heating the surrounding battery cells and this mechanism is called burst disc rupture.

PROBLEM TO BE SOLVED BY PRESENT INVENTION:
Currently the users are being informed about the fire hazard at a very late stage and the users are not given enough time to move away from the electric vehicle. The damage is considered catastrophic since the users are being informed later and might lead to loss of life.

Hence, it is a primary objective of the current invention to provide a solution that overcomes such limitations by detecting early and informing the users much ahead even before the fire spreads into the battery pack or even if the fire is supposed to happen.

The current battery systems have sensors for detecting faults in the battery module which are placed in such a way that they could fail the detection of a faulty battery cell and thereby failing to warn the user at an early stage.

Thus, it is another objective of the current invention to place the sensors in a strategically determined location to detect every faulty battery cell without fail as they are vital in detecting and informing the users about the fire hazards at an early stage.

Also, currently the battery packs use many sensors to detect the faulty battery cells, which is difficult to implement, and provide stable connections with the BMS board. This also increases costs significantly.

Thus, it is another objective of the current invention to minimize the number of sensors in the battery packs by placing them strategically and reducing the cost involved.

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 method and system to detect thermal runaway at an early stage in a battery pack. The system comprises of the following. A plurality of battery cells in a battery module are connected with each other through a thermo-electric conductor in the battery module. One or more temperature sensors are placed on the thermo-electric conductor in a strategically determined location, such that every battery cell in the battery module is within the detection range of the corresponding temperature sensor. The one or more faulty battery cells among the plurality of battery cells release heat during initial venting state, where the initial venting state is the release of hot gases and electrolyte from the one or more faulty battery cells before thermal runaway. The thermo-electric conductor rapidly absorbs heat released by the one or more faulty battery cells. The one or more temperature sensors detect a fault signal through the rapidly absorbed heat at the initial venting state of the one or more faulty battery cells. A battery management system (BMS) board receives the detected fault signal from the one or more temperature sensors. A control unit (CU) receives the fault signal transmitted from the BMS board for alerting the users.

As per another embodiment of the current invention, a method to detect thermal runaway at an early stage in a battery pack is disclosed. The method comprises of the following. Connecting a plurality of battery cells in a battery module with each other through a thermo-electric conductor in the battery module. Placing one or more temperature sensors on the thermo-electric conductor in a strategically determined location, such that every battery cell in the battery module is within the detection range of the corresponding temperature sensor. Releasing of heat by the one or more faulty battery cells among the plurality of battery cells during initial venting state, where the initial venting state is the release of hot gases and electrolyte from the one or more faulty battery cells before thermal runaway. Absorbing heat released by the one or more faulty battery cells rapidly by the thermo-electric conductor. Detecting a fault signal through the rapidly absorbed heat at the initial venting state of the one or more faulty battery cells by the one or more temperature sensors. Receiving the detected fault signal from the one or more temperature sensors by a battery management system (BMS) board. Transmitting the received fault signal from the BMS board to a control unit (CU) for alerting the users.

As per first 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 second embodiment of the current invention, the one or more temperature sensors may be thermistors, thermocouple, resistance temperature detector (RTD).

As per third embodiment of the current invention, the alert of the fault signal for the users maybe audio, visual or haptic.

As per fourth 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.

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 representation illustrating connecting a plurality of battery cells with each other through a thermo-electric conductor in the battery module, according to an embodiment of the present invention.

Figure 2 is a schematic representation illustrating placing of temperature sensors on the thermo-electric conductor in a strategically determined location, according to an embodiment of the present invention.

Figure 3 is a flow diagram representing detection of a thermal runaway at an early stage in a battery pack, 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 method and system to detect thermal runaway at an early stage 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 and Figure 2, a system to detect thermal runaway at an early stage in a battery pack (101) is disclosed. The system comprises of the following. A plurality of battery cells (102) in a battery module (103) are connected with each other through a thermo-electric conductor (104) in the battery module (103). One or more temperature sensors (105) are placed on the thermo-electric conductor (104) in a strategically determined location, such that every battery cell (102) in the battery module (103) is within the detection range of the corresponding temperature sensor (105). The one or more faulty battery cells (102) among the plurality of battery cells (102) release heat during initial venting state, where the initial venting state is the release of hot gases and electrolyte from the one or more faulty battery cells (102) before thermal runaway. The thermo-electric conductor (104) rapidly absorbs heat released by the one or more faulty battery cells (102). The one or more temperature sensors (105) detect a fault signal through the rapidly absorbed heat at the initial venting state of the one or more faulty battery cells (102). A battery management system (BMS) board (106) receives the detected fault signal from the one or more temperature sensors (105). A control unit (CU) (107) receives the fault signal transmitted from the BMS board (106) for alerting the users.

As per Figure 3, a method to detect thermal runaway at an early stage in a battery pack (101) is disclosed. The method comprises of the following. Connecting a plurality of battery cells (102) in a battery module (103) with each other through a thermo-electric conductor (104) in the battery module (103). Placing one or more temperature sensors (105) on the thermo-electric conductor (104) in a strategically determined location, such that every battery cell (102) in the battery module (103) is within the detection range of the corresponding temperature sensor (105). Releasing of heat by the one or more faulty battery cells (102) among the plurality of battery cells (102) during initial venting state, where the initial venting state is the release of hot gases and electrolyte from the one or more faulty battery cells (102) before thermal runaway. Absorbing heat released by the one or more faulty battery cells (102) rapidly by the thermo-electric conductor (104). Detecting a fault signal through the rapidly absorbed heat at the initial venting state of the one or more faulty battery cells (102) by the one or more temperature sensors (105). Receiving the detected fault signal from the one or more temperature sensors (105) by a battery management system (BMS) board (106). Transmitting the received fault signal from the BMS board (106) to a control unit (CU) (107) for alerting the users.

As per first embodiment of the current invention, the one or more faulty battery cells (102) may be due to overheating, internal short-circuit, over charging, over discharging, mechanical abuse.

As per second embodiment of the current invention, the one or more temperature sensors (105) may be thermistors, thermocouple, resistance temperature detector (RTD).

As per third embodiment of the current invention, the alert of the fault signal for the users maybe audio, visual or haptic.

As per fourth embodiment of the current invention, the thermo-electric conductor (104) may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.

FURTHER ADVANTAGES OF THE INVENTION
The current invention provides a solution that overcomes such limitations by detecting early and informing the users much ahead even before the fire spreads into the battery pack or even if the fire is supposed to happen. The sensors are placed in a strategically determined location to detect every faulty battery cell without fail as they are vital in detecting and informing the users about the fire hazards at an early stage. The current invention also minimizes the number of sensors in the battery packs by placing them strategically and reducing the cost involved.

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 plurality of battery cells 102
3. a battery module 103
4. a thermo-electric conductor 104
5. one or more temperature sensors 105
6. a battery management system (BMS) board 106
7. a control unit (CU) 107
, C , Claims:CLAIMS
We claim:

1. A method to detect thermal runaway at an early stage in a battery pack (101), the method comprising:
connecting a plurality of battery cells (102) in a battery module (103) with each other through a thermo-electric conductor (104) in the battery module (103);
placing one or more temperature sensors (105) on the thermo-electric conductor (104) in a strategically determined location, such that every battery cell (102) in the battery module (103) is within the detection range of the corresponding temperature sensor (105);
releasing of heat by the one or more faulty battery cells (102) among the plurality of battery cells (102) during initial venting state, where the initial venting state is the release of hot gases and electrolyte from the one or more faulty battery cells (102) before thermal runaway,
characterized in that,
absorbing heat released by the one or more faulty battery cells (102) rapidly by the thermo-electric conductor (104),
detecting a fault signal through the rapidly absorbed heat at the initial venting state of the one or more faulty battery cells (102) by the one or more temperature sensors (105),
receiving the detected fault signal from the one or more temperature sensors (105) by a battery management system (BMS) board (106),
transmitting the received fault signal from the BMS board (106) to a control unit (CU) (107) for alerting the users.

2. The method as claimed in claim 1, wherein the one or more faulty battery cells (102) may be due to overheating, internal short-circuit, over charging, over discharging, mechanical abuse.

3. The method as claimed in claim 1, wherein alert of the fault signal for the users maybe audio, visual or haptic.

4. A system to detect thermal runaway at an early stage in a battery pack (101), the system comprising:
a plurality of battery cells (102) in a battery module (103) are connected with each other through a thermo-electric conductor (104) in the battery module (103);
one or more temperature sensors (105) are placed on the thermo-electric conductor (104) in a strategically determined location, such that every battery cell (102) in the battery module (103) is within the detection range of the corresponding temperature sensor (105);
the one or more faulty battery cells (102) among the plurality of battery cells (102) release heat during initial venting state, where the initial venting state is the release of hot gases and electrolyte from the one or more faulty battery cells (102) before thermal runaway,
characterized in that,
the thermo-electric conductor (104) rapidly absorbs heat released by the one or more faulty battery cells (102),
the one or more temperature sensors (105) detect a fault signal through the rapidly absorbed heat at the initial venting state of the one or more faulty battery cells (102),
a battery management system (BMS) board (106) receives the detected fault signal from the one or more temperature sensors (105),
a control unit (CU) (107) receives the fault signal transmitted from the BMS board (106) for alerting the users.

5. The system as claimed in claim 4, wherein the one or more temperature sensors (105) may be thermistors, thermocouple, resistance temperature detector (RTD).

6. The system as claimed in claim 4, wherein the thermo-electric conductor (104) may be a metal core printed circuit board (MCPCB), FR4 PCB, nickel strip, copper strip, aluminium plate.