WO2022088320A1

WO2022088320A1 - Battery module, battery pack and battery thermal runaway detection method therefor

Info

Publication number: WO2022088320A1
Application number: PCT/CN2020/130808
Authority: WO
Inventors: 杨明平; 何亚飞; 宋状; 白玉龙; 李登科; 朱圣法
Original assignee: 远景动力技术(江苏)有限公司; 远景睿泰动力技术(上海)有限公司
Priority date: 2020-10-27
Filing date: 2020-11-23
Publication date: 2022-05-05
Also published as: CN112259900A

Abstract

Disclosed in the present invention are a battery module, a battery pack and a battery thermal runaway detection method therefor. The battery module of the battery pack comprises: a plurality of battery cells laterally adjacent to each other in sequence, one side of each battery cell being provided with an explosion-proof valve; a busbar support of a plate shape provided adjacent to the sides of the battery cells provided with the explosion-proof valves and equipped with openings in the positions corresponding to the explosion-proof valves; a circuit sampling plate installed on the surface of the busbar support and having a main body and at least one weakening part integrally connected to the main body, the at least one weakening part corresponding to the positions of the openings. The battery module can obtain a warning signal of battery cell abnormality, and is high in early warning accuracy and low in detection cost.

Description

Battery module, battery pack and battery thermal runaway detection method

Cross-reference to related applications

This patent application claims the priority of the Chinese patent application filed on October 27, 2020 with the application number 2020111627271 and the invention titled "Battery Module, Battery Pack and Battery Thermal Runaway Detection Method". Incorporated herein by reference.

technical field

The invention relates to the technical field of batteries, in particular to a battery module, a battery pack and a battery thermal runaway detection method.

Background technique

Lithium-ion battery thermal runaway causes vehicles to burn out from time to time. How to prevent battery thermal runaway is an important research and development direction for many car companies and battery manufacturers. Thermal runaway of the battery occurs with gas ejection, the temperature will increase, and the voltage will decrease. The thermal runaway monitoring of the battery usually uses the gas pressure sensor in the battery pack to detect the gas pressure, and simultaneously detects the voltage and temperature of the battery cell, and makes a comprehensive judgment based on the detection results of the three. However, in the existing thermal runaway monitoring scheme, due to the problems of the device itself, one or more false alarms of the three measured values of gas pressure value, voltage or temperature will be caused, which will affect the accuracy of cell monitoring and cause unnecessary Check the cost, resulting in a poor user experience.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a battery module, a battery pack and a battery thermal runaway detection method. The battery module of the battery pack can obtain warning signals of abnormal cells, and has high warning accuracy and low detection cost.

In order to solve the above technical problems, an embodiment of the present invention provides a battery module, including:

a plurality of battery cells, the plurality of battery cells are laterally adjacent to each other in sequence, and one side of each battery cell is provided with an explosion-proof valve;

a busbar support, the busbar support is plate-shaped and is disposed adjacent to the side of the plurality of cells with the explosion-proof valve, and the busbar support is provided with an opening at a position corresponding to the explosion-proof valve;

A circuit sampling board, the circuit sampling board is mounted on the surface of the busbar support, the circuit sampling board has a main body and at least one weakened part integrally connected with the main body, the at least one weakened part is connected to the opening corresponding to the location.

An embodiment of the present invention also provides a battery pack, the battery pack includes the above-mentioned battery module.

An embodiment of the present invention further provides a battery thermal runaway detection method, which is applied to a battery module, wherein the battery module includes: a plurality of cells, the plurality of cells are laterally adjacent to each other in sequence, and each cell An explosion-proof valve is arranged on one side of the battery; a busbar support, the busbar support is plate-shaped and is arranged adjacent to the side of the plurality of cells with the explosion-proof valve, and the busbar support is corresponding to the explosion-proof valve. An opening is provided at the position of the circuit sampling plate; the circuit sampling plate is mounted on the surface of the busbar support, and the circuit sampling plate has a main body and at least one weakened part integrally connected with the main body, the at least one weakened part part corresponds to the position of the opening;

The battery thermal runaway detection method includes: detecting the line signal of the weakened part; and sending a feedback signal to a management system when the line signal of the weakened part changes.

An embodiment of the present invention further provides a battery thermal runaway detection method, which is applied to a battery module, wherein the battery module includes: a plurality of cells, the plurality of cells are laterally adjacent to each other in sequence, and each cell An explosion-proof valve is arranged on one side of the battery; a busbar support, the busbar support is plate-shaped and is arranged adjacent to the side of the plurality of cells with the explosion-proof valve, and the busbar support is corresponding to the explosion-proof valve. There is an opening at the position of the circuit sampling plate; the circuit sampling plate is installed on the surface of the busbar support, and the circuit sampling plate has a main body and a plurality of weakened parts; wherein, the two ends of each weakened part are respectively connected with the The main body is integrally connected and corresponds to the position of the opening, the weakened portion extends in a direction intersecting with the arrangement direction of the battery cells, and the number of the plurality of weakened portions and the battery cells is the same;

The battery thermal runaway detection method includes: connecting the plurality of weakened parts in series with resistors with different resistance values respectively, and detecting the total resistance value of the parallel connection of the resistances of the plurality of weakened parts; when the total resistance value changes, The corresponding broken weakened portion is determined according to the total resistance value.

The battery module sets a weakening part on the circuit sampling board, and uses the gas generated inside the battery cell to break through the explosion-proof valve to break the weakening part to issue a warning signal of abnormal battery core, and the warning rate is high.

In some embodiments, the at least one weakened portion is one weakened portion, and one end of the one weakened portion is integrally connected with the main body and extends along the direction of the cell arrangement.

In some embodiments, the at least one weakened portion includes a plurality of weakened portions, two ends of each weakened portion are respectively integrally connected with the main body, and correspond to the positions of the openings, and the weakened portions are located along the The electric cores are arranged in a direction intersecting the direction extending, wherein the number of the weakened parts is the same as the number of the electric cores.

In some embodiments, the plurality of weakened parts are respectively connected in series with resistors with different resistance values.

In some embodiments, the main body includes a base portion and two connecting portions extending from the base portion along the cell arrangement direction, and two ends of the weakened portion are respectively connected to the two connecting portions.

In some embodiments, the main body includes two base portions and at least one connecting portion extending from the two base portions along the cell arrangement direction and connecting the two base portions; the at least one weakened portion is two A weakened portion, the two weakened portions are respectively integrally connected with the two base portions and extend along the arrangement direction of the battery cells.

In some embodiments, the size of the opening is not smaller than the size of the explosion-proof valve.

In some embodiments, the circuit sampling board is further provided with at least one sampling part, the weakening part is connected with the at least one sampling part, and a sampling induction part is arranged on the sampling part.

In some embodiments, the size of the weakened portion along a direction perpendicular to the arrangement direction of the cells is 1-3 mm.

In some embodiments, the size of the weakened portion along the arrangement direction of the cells is 1-3 mm.

In some embodiments, the weakened portion has a narrowed section at a portion corresponding to the opening.

Description of drawings

1 is a schematic structural diagram of a battery module according to an embodiment of the present invention;

2 is a schematic structural diagram of a circuit sampling board of a battery module according to an embodiment of the present invention;

3 is a schematic structural diagram of another modification of the circuit sampling board of the battery module according to the embodiment of the present invention;

4 is a schematic structural diagram of a bus bar support according to an embodiment of the present invention;

5 is a schematic flowchart of a battery thermal runaway detection method according to an embodiment of the present invention;

FIG. 6 is a schematic flowchart of a battery thermal runaway detection method according to another embodiment of the present invention.

specific embodiment

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to more clearly understand the objects, features and advantages of the present invention. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solutions of the present invention.

In the following description, for the purpose of illustrating various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of these specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Unless the context requires otherwise, throughout the specification and claims, the word "comprising" and variations thereof, such as "comprising" and "having", should be construed in an open, inclusive sense, i.e., should be interpreted as "including, but not limited to".

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout the specification are not necessarily all referring to the same embodiment. Additionally, the particular features, structures or characteristics may be combined in any manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a" and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

In the following description, in order to clearly show the structure and working mode of the present invention, many directional words will be used for description, but "front", "rear", "left", "right", "outer", "inner" should be "," "outward", "inward", "up", "down", "vertical", "horizontal" and other words should be understood as convenient terms, and should not be understood as limiting words.

The battery module of the embodiment of the present invention includes: a plurality of battery cells, which are laterally adjacent to each other in sequence, and an explosion-proof valve is configured on one side of each battery cell; a bus bar support, the bus bar support is plate-shaped and The side of the plurality of cells with the explosion-proof valve is adjacently arranged, and the busbar support is provided with an opening at the position corresponding to the explosion-proof valve; the circuit sampling board, the circuit sampling board is installed on the surface of the busbar support, and the circuit sampling board has a main body and a connection with the main body. At least one weakened portion is integrally connected, and the weakened portion corresponds to the position of the opening.

Embodiments of the present invention are described below with reference to the accompanying drawings. In this embodiment, as shown in FIG. 1 , the battery module of this embodiment includes a plurality of battery cells (not shown in the figure), a bus bar support 1 , a circuit sampling board 2 , a bus bar 3 , a connecting piece 4 and an interface 5. The bus bar support 1 is in a substantially rectangular plate shape, and covers the top of the cells, and is arranged adjacent to a plurality of cells, and each cell is arranged adjacent to each other on a side surface in sequence. The side of the cell facing the bus bar support 1 is provided with a positive pole and a negative pole (not shown in the figure), which are respectively arranged at two sides close to the cell. The positive poles and the negative poles of the adjacent cells are connected by the bus bars 3 , and the series connection between the respective cells can be realized through the plurality of the bus bars 3 . The circuit sampling board 2 is connected to the bus bar 3 through the connecting piece 4, and collects the voltage on the bus bar, that is, obtains the voltage of the corresponding cell. The obtained voltage can finally be output to an external controller through the interface 5 . The side of each cell facing the busbar support 1 is also provided with an explosion-proof valve (not shown in the figure), and the busbar support 1 is provided with a plurality of openings 11 corresponding to the explosion-proof valves of each cell. When the air pressure is too high, the expanding gas can penetrate the explosion-proof valve and escape through the opening 11, so as to release the pressure without causing the self-explosion of the cell. The opening 11 may be set in an ellipse shape or in other shapes, and may be set according to the shape of the explosion-proof valve, which is not limited here.

In the illustrated embodiment, the battery module is arranged with two circuit sampling boards, namely the circuit sampling board 2 and the circuit sampling board 6 . In the embodiment shown, the circuit sampling plate 2 and the circuit sampling plate 6 are respectively arranged between two columns of bus bars. The circuit sampling board usually adopts a flexible printed circuit board (FPC). The flexible printed circuit board can better fit on the surface of the busbar support 1 and can more effectively utilize the internal space of the battery module. As shown in FIG. 2 , the circuit sampling plate 2 in the illustrated embodiment includes a base portion 21 , two connecting portions 22 and a weakening portion 23 . Specifically, the base portion 21 is connected to the two connection portions 22 , and also has a portion connected to the interface 5 . The two connecting portions 22 extend from the base portion 21 along the cell arrangement direction, and the two connecting portions 22 are integrally connected with the base portion 21 of the circuit sampling board 2 . The base portion 21 and the two connecting portions 22 constitute the main body of the circuit sampling board 2, which is substantially "U" shaped, but it should be understood that the main body may also be in other shapes such as rectangles. In the illustrated embodiment, the weakened portion 23 is in the shape of a strip, and one end of the weakened portion 23 is integrally connected with the main body and extends along the direction of cell arrangement. The weakened portion 23 corresponds to the position of the opening 11 of the bus bar support 1, and the weakened portion 23 covers at least part of the opening 11. When the pressure of the inflation gas inside the cell is too large, the inflation gas can pass through the explosion-proof valve and the opening 11 and break the weakened part 23 . The weakening part 23 is provided with a corresponding circuit. When the weakening part 23 is broken, the corresponding circuit line is also disconnected. The interruption signal is output to the controller through the interface 5, and the controller can output a warning signal to the user.

The width of the weakened portion 23 along the direction perpendicular to the arrangement direction of the cells is 1-3 mm, preferably 2 mm. The weakened portion 23 of the above-mentioned size will be broken in time when the expanding gas rushes out of the opening 11, so as not to cause the occurrence of the weakened portion. 23 The size is too large to be broken in time, and the weakened part below the above size is easily torn due to vibration. Such an arrangement can monitor the internal working state of the battery cell through a relatively simple circuit, and the cost is low.

In some embodiments, the weakened portion 23 has a narrowed section at the portion corresponding to the opening 11 , that is, the width of the weakened portion corresponding to the opening is smaller than the width of other positions. It will be broken in time to reduce the possibility of detection failure.

In another embodiment, as shown in FIG. 3 , the circuit sampling board 2 has two sampling parts 24 , the weakening parts 23 are respectively connected to the two sampling parts 24 , and the sampling parts 24 are provided with sampling induction parts 25 . Specifically, the circuit sampling board 2 includes a base part 21 , two connecting parts 22 and a weakening part 23 , wherein the base part 21 and the two connecting parts 22 constitute the main body of the circuit sampling board 2 . The two connecting portions 22 extend from the base portion 21 along the cell arrangement direction, and the two connecting portions 22 are integrally connected with the base portion 21 of the circuit sampling board 2 . The sampling part 24 is connected to the weakening part 23 through the sampling connecting part 26 . The sampling part 24 may or may not be connected to the connection part 22 . The sampling part 24 is also provided with a sampling induction part 25 , which is preferably disposed at the end of the sampling part 24 . The sampling induction part 25 is provided on the surface of the cell, and is used to detect the temperature of the surface of the cell. The sampling induction part 25 can be fixed to the surface of the cell by means of fasteners. In this embodiment, by connecting the sampling part 24 to the weakening part 23, when the weakening part is broken, it is detected that the signal of the sampling part is interrupted, and a warning signal of abnormal cell can be issued by the received feedback signal. As a result, the lines of the sampling part and the lines of the weakening part are assembled together, and part of the detection lines are omitted, thereby simplifying the lines and reducing the cost.

In addition, it should be noted that the flexible printed circuit board (FPC) includes an insulating film and a conductor portion in the insulating film, that is, the above-mentioned base, connecting portion, weakened portion, and sampling portion all include the insulating film and the conductor portion in the insulating film. When it is broken, the inner conductor part is also disconnected, that is, the electrical connection is disconnected, the following is similar and will not be repeated.

The base portion 61 and the two connecting portions 62 of the circuit sampling board 6 are substantially the same as the base portion 21 and the two connecting portions 22 of the circuit sampling board 2 , which will not be repeated here. The main difference is that the weakened portion 63 of the circuit sampling board 6 is along the The direction intersecting with the arrangement direction of the cells extends, and both ends of each weakened portion 63 are respectively connected to the two connection portions 62 . Wherein, the width of the weakened portion 63 along the cell arrangement direction is 1-3 mm, preferably 2 mm. In some embodiments, the weakened portion 63 has a narrowed section at the portion corresponding to the opening 11 , which is more beneficial to ensure that the inflation gas will be broken in time when it rushes out of the opening 11 , thereby reducing the possibility of detection failure.

In addition, the weakened portion 63 is not necessarily completely orthogonal to the arrangement direction of the cells, and can also present an angle of, for example, 45 degrees or other angles, but it must be ensured that each weakened portion 63 covers part of the opening 11 , wherein the number of the weakened portion 63 is the same as the opening 11 . The number of batteries or the number of batteries is the same, and an independent circuit can be set in each weakening part 63. When the corresponding circuit signal is interrupted, the corresponding faulty battery can be located, thereby realizing the monitoring of each battery. , which is convenient for users to maintain.

The circuit sampling board 2 and the circuit sampling board 6 are installed on the bus bar support 1 as shown in FIG. 3 and are arranged along the longitudinal direction of the bus bar support 1. The circuit sampling board 2 and the circuit sampling board 6 are respectively installed on the respective tabs of the battery cells. between the columns. The installation form of the circuit sampling board is not limited to the coexistence form in FIG. 1 . For example, it is also possible to install only the circuit sampling board 2 on the bus bar support, or only install the circuit sampling board 6, which is not limited here.

By setting a weakening part on the circuit sampling board, the battery module uses the gas generated inside the battery cell to open the explosion-proof valve to break the weakening part to send out a warning signal of abnormal battery core. The combination of some pressure, temperature and voltage measurement methods can greatly reduce the probability of false alarms.

In some embodiments, the body of the circuit sampling board includes two bases and at least one connection. Specifically, the at least one connecting portion extends along the arrangement direction of the respective battery cells, and the two base portions are respectively located at two ends of the at least one connecting portion. At least one connection part may be one connection part or two connection parts. For example, one connecting portion extends along the cell arrangement direction and connects the two base portions. The circuit sampling board is also provided with two weakened parts, the two weakened parts extend along the cell arrangement direction and are integrally connected with the two base parts respectively, and the two weakened parts are respectively connected to different areas (for example, the first area position and the second area position). ) corresponding to the positions of the openings, but the two weakened parts do not repeatedly correspond to the same opening, and such an arrangement can locate the problematic cell to a relatively specific area.

In addition, the main body 21 is also provided with a plurality of positioning holes, which are used to cooperate with the bosses on the busbar support 1 to realize the positioning and installation of the circuit sampling board 2. Some positioning holes are slightly larger than the bosses to provide a certain space redundancy and facilitate the assembly.

The present invention also provides a battery pack, which includes the above-mentioned battery module, which includes a battery cell, a bus bar, a bus bar support, a connecting piece, a circuit sampling board, an interface and other components. The battery module of the battery pack sets a weakening part on the circuit sampling board, and uses the gas generated inside the battery cell to open the explosion-proof valve to break the weakening part to send out a warning signal of abnormal battery cell, and the warning accuracy rate is high.

The embodiment of the present invention also provides a battery thermal runaway detection method, which is applied to a battery module. The battery module includes: a plurality of battery cells, the plurality of battery cells are laterally adjacent to each other in sequence, and one side of each battery cell is configured with a Explosion-proof valve; busbar bracket, the busbar bracket is plate-shaped and is arranged adjacent to the side of the plurality of cells with explosion-proof valves, and the busbar bracket is provided with an opening at the position corresponding to the explosion-proof valve; circuit sampling board, circuit sampling board installation On the surface of the busbar support, the circuit sampling board has a main body and at least one weakened part integrally connected with the main body, and the weakened part corresponds to the position of the opening;

The battery thermal runaway detection method includes: detecting the line signal of the weakened part; when the line signal of the weakened part changes, sending a feedback signal to the management system.

As shown in Figure 5, the battery thermal runaway detection method includes:

Step 201: Detect the line signal of the weakened part.

Specifically, the weakened part 23 is connected with the circuit sampling board 2 to form a circuit loop. When in working state, the circuit is kept in an open state; when the battery cell is thermally out of control, the expanding gas rushes out of the battery cell and blows the weakened part out, and the circuit is routed by The path becomes disconnected.

Step 202: When the line signal of the weakening part changes, send a feedback signal to the management system.

Specifically, when it is determined that the line signal of the weakening part is disconnected, that is, when the system does not receive the line signal, the feedback signal can be sent to the battery management system BMS, and the BMS determines that the weakening part is disconnected, that is, the battery is in Thermal runaway condition.

The battery thermal runaway detection method of the battery module sets a weakening part on the circuit sampling board, and uses the gas generated inside the battery cell to open the explosion-proof valve to break the weakening part to issue a warning signal of abnormal battery cell, and the warning rate is high. .

It should be noted that the relevant technical details mentioned in the above embodiments are still valid in this implementation manner, and are not repeated here in order to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the above embodiments.

In another embodiment of the battery thermal runaway detection method, the battery module includes: a plurality of battery cells, the plurality of battery cells are laterally adjacent to each other in sequence, and an explosion-proof valve is arranged on one side of each battery cell; The row bracket is plate-shaped and is arranged adjacent to the side of the plurality of cells with explosion-proof valves, and the busbar bracket is provided with an opening at the position corresponding to the explosion-proof valve; the circuit sampling board is installed on the surface of the busbar bracket, and the circuit The sampling plate has a main body and a plurality of weakened parts; wherein, two ends of each weakened part are integrally connected with the main body respectively and correspond to the positions of the openings; The number of parts and cells is the same;

In this embodiment, as shown in Figure 6, the battery thermal runaway detection method comprises the following steps:

Step 301 : Connect the plurality of weakened parts in series with resistors with different resistance values, respectively, and detect the total resistance value of the parallel connection of the resistances of the plurality of weakened parts.

Specifically, in this embodiment, a resistor with different resistance values can be connected in series in the circuit of each weakened part. For example, if there are three weakened parts on the circuit sampling board in total, namely the first weakened part and the second weakened part resistors of 1Ω, 2Ω and 3Ω are connected in series in the lines of the first, second and third weakened parts respectively, and the total resistance of the parallel circuit formed by the three weakened parts is 0.545Ω. When the first weakened part is broken, the total resistance of the circuit becomes 1.2Ω; when the second weakened part is broken, the total resistance of the circuit becomes 0.75Ω; when the third weakened part is broken, the total resistance of the circuit becomes 0.666Ω ; When the first weakened part and the second weakened part are broken together, the total resistance of the circuit becomes 3Ω, and so on. By analogy, the total resistance value of the parallel circuit is detected by connecting resistors with different resistance values in series in the lines of the weakened portion, and then connecting each line of the weakened portion in parallel.

Step 302: When the total resistance value changes, determine the corresponding broken weakened portion according to the total resistance value.

Specifically, when one or more of the weakened parts are disconnected, the total resistance value of the above-mentioned parallel circuit will change, and any or any of the weakened parts will have a corresponding total resistance value after disconnection. The obtained total resistance value is obtained, that is, the position of the corresponding fractured weakened part is obtained. This method has a high early warning accuracy rate, and at the same time simplifies the control circuit and reduces the cost.

The preferred embodiments of the present invention have been described in detail above, but it is to be understood that aspects of the embodiments can be modified, if desired, to employ aspects, features and concepts of various patents, applications and publications to provide additional embodiments.

These and other changes can be made to the embodiments in light of the above detailed description. In general, in the claims, the terms used should not be construed as limiting to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments, along with all equivalents to which these claims are entitled scope.

Claims

A battery module, characterized in that, comprising:

a plurality of battery cells, the plurality of battery cells are laterally adjacent to each other in sequence, and one side of each battery cell is provided with an explosion-proof valve;

a busbar support, the busbar support is plate-shaped and is disposed adjacent to the side of the plurality of cells with the explosion-proof valve, and the busbar support is provided with an opening at a position corresponding to the explosion-proof valve;

A circuit sampling board, the circuit sampling board is mounted on the surface of the busbar support, the circuit sampling board has a main body and at least one weakened part integrally connected with the main body, the at least one weakened part is connected to the opening corresponding to the location.
The battery module according to claim 1, wherein the at least one weakened portion is a weakened portion, and one end of the one weakened portion is integrally connected with the main body and extends along the arrangement direction of the cells.
The battery module according to claim 1, wherein the at least one weakened portion is a plurality of weakened portions, and two ends of each weakened portion are respectively integrally connected with the main body and are in the same position as the opening. Correspondingly, the plurality of weakened parts extend in a direction intersecting with the arrangement direction of the battery cells, wherein the number of the plurality of weakened parts and the battery cells is the same.
The battery module according to claim 3, wherein the plurality of weakened parts are respectively connected in series with resistors with different resistance values.
The battery module according to claim 3, wherein the main body comprises a base portion and two connecting portions extending from the base portion along the cell arrangement direction, and two ends of the weakened portion are respectively connected to the Describe the two connections.
The battery module according to claim 1, wherein the main body comprises two bases and at least one connecting part extending from the two bases along the cell arrangement direction and connecting the two bases;

The at least one weakened portion is two weakened portions, and the two weakened portions are respectively integrally connected with the two base portions and extend along the arrangement direction of the battery cells.
The battery module according to claim 1, wherein the size of the opening is not smaller than the size of the explosion-proof valve.
The battery module according to claim 2, wherein the circuit sampling board is further provided with at least one sampling part, the weakening part is connected to the at least one sampling part, and the sampling part is provided with a sampling sensor department.
The battery module according to claim 2, wherein the dimension of the weakened portion along the vertical direction of the arrangement direction of the battery cells is 1-3 mm.
The battery module according to claim 3, wherein the size of the weakened portion along the arrangement direction of the battery cells is 1-3 mm.
The battery module of claim 1, wherein the weakened portion has a narrowed section at a portion corresponding to the opening.
A battery pack, characterized by comprising the battery module according to any one of claims 1-11.
A battery thermal runaway detection method, characterized in that it is applied to a battery module, the battery module comprising:

a plurality of battery cells, the plurality of battery cells are laterally adjacent to each other in sequence, and one side of each battery cell is provided with an explosion-proof valve;

a bus bar bracket, the bus bar bracket is plate-shaped and is arranged adjacent to the side of the plurality of battery cells where the explosion-proof valve is provided, and the bus-bar bracket is provided with an opening at a position corresponding to the explosion-proof valve;

A circuit sampling board, the circuit sampling board is mounted on the surface of the busbar support, the circuit sampling board has a main body and at least one weakened part integrally connected with the main body, the at least one weakened part is connected to the opening of the opening corresponding to the location;

The battery thermal runaway detection method includes: detecting a line signal of the weakened part; and sending a feedback signal to a management system when the line signal of the weakened part changes.
A battery thermal runaway detection method, characterized in that it is applied to a battery module, the battery module comprising:

a plurality of battery cells, the plurality of battery cells are laterally adjacent to each other in sequence, and one side of each battery cell is provided with an explosion-proof valve;

a bus bar bracket, the bus bar bracket is plate-shaped and is arranged adjacent to the side of the plurality of battery cells where the explosion-proof valve is provided, and the bus-bar bracket is provided with an opening at a position corresponding to the explosion-proof valve;

a circuit sampling board, the circuit sampling board is mounted on the surface of the busbar support, the circuit sampling board has a main body and a plurality of weakened parts;

Wherein, both ends of each weakened portion are integrally connected to the main body and correspond to the positions of the openings, the weakened portion extends in a direction intersecting with the arrangement direction of the battery cells, and the plurality of weakened portions are The number of parts is the same as the number of the battery cells;

The battery thermal runaway detection method includes: connecting the plurality of weakened parts in series with resistors with different resistance values respectively, and detecting the total resistance value of the parallel connection of the resistances of the plurality of weakened parts;

When the total resistance value changes, the corresponding broken weakened portion is determined according to the total resistance value.