A battery pack with the function of detecting thermal runaway signals

Abstract

The present invention relates to the field of battery technology, and in particular to a battery pack with a function of detecting thermal runaway signals, comprising: a battery pack body, a flow guide assembly, and a plurality of sensors; the flow guide assembly comprises a heat insulating sheet and a flow guide member, the heat insulating sheet and the flow guide member are an integrated structure, and the flow guide member is arranged at the bottom of the heat insulating sheet; the heat insulating sheet is arranged on the battery pack body; a plurality of sensors are arranged around the heat insulating sheet, wherein at least two of the sensors are arranged at the end of the flow guide member. By means of the flow guide assembly and the plurality of sensors provided by the present invention, no matter where a battery in the battery pack has thermal runaway, gas with a certain airflow velocity can be quickly guided to the sensor position along the airflow channel between the flow guide members, thereby quickly detecting the thermal runaway signal and reporting the thermal runaway signal as an alarm message to the entire vehicle, so as to remind the occupants to evacuate and ensure the safety of the occupants.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery pack with a function of detecting thermal runaway signals. Background Art

[0002] With the release of the new national standard "GB 38031-2020 Safety Requirements for Power Batteries for Electric Vehicles", it is required that a thermal event alarm signal should be provided five minutes before the thermal runaway of a single cell causes heat diffusion and thus causes danger to the passenger compartment. Therefore, we need to make timely and effective judgments on thermal runaway events of battery systems.

[0003] At present, the battery system status is mainly detected through the BMS acquisition module's voltage per string and 2-4 temperature acquisition points arranged on the module. When a battery cell in the battery system has thermal runaway, the voltage of a string will jump, but due to the limited number of temperature sensor points and the slow heat transfer in the early stage of thermal runaway, the temperature signal cannot be collected in time, and at least the voltage and temperature signals need to reach a certain threshold at the same time to be judged as thermal runaway. Therefore, the thermal runaway signal cannot be collected quickly or is falsely reported, which brings some troubles to the occupants; however, timely and effective transmission of thermal runaway signals cannot be achieved with existing technologies.

[0004] The patent document with application number 201921985375.2 discloses a battery pack for new energy vehicles that can delay thermal runaway. It discloses a battery pack for new energy vehicles that can delay thermal runaway, which belongs to the technical field of new energy vehicle battery packs. It includes a shell and multiple battery modules arranged in the shell. The battery module has built-in voltage acquisition module and temperature sensor. Due to the limited number of temperature sensor points and slow heat transfer in the early stage of thermal runaway, the thermal runaway signal cannot be detected quickly and effectively. There is no technical inspiration in the combination of the diversion structure in this application and the prior art. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The present invention provides a battery pack with a function of detecting thermal runaway signals, aiming to solve the problem that the existing battery pack cannot timely and effectively transmit thermal runaway signals.

[0007] (II) Technical solution

[0008] In order to achieve the above-mentioned purpose, the main technical solutions adopted by the present invention include: a battery pack body, a flow guide component and a plurality of sensors;

[0009] The flow guide assembly includes a heat insulating sheet and a flow guide member, the heat insulating sheet and the flow guide member are an integrated structure, and the flow guide member is arranged at the bottom of the heat insulating sheet; the heat insulating sheet is arranged on the battery pack body;

[0010] A plurality of the sensors are arranged at the periphery of the heat insulation sheet, wherein at least two of the sensors are arranged at the end of the guide member.

[0011] Preferably, the guide member includes a first guide plate, a second guide plate and a third guide plate. The first guide plate, the second guide plate and the third guide plate are all arc structures symmetrical at both ends and can form air flow channels with each other. The first guide plate, the second guide plate and the third guide plate are symmetrically spaced about the diagonal of the thermal insulation plate.

[0012] Preferably, the inflection points of the first guide plate, the second guide plate and the third guide plate are all arc-shaped, and the depths of the first guide plate, the second guide plate and the third guide plate are 2 mm to 20 mm.

[0013] Preferably, the guide member includes a fourth guide plate, a fifth guide plate and a guide straight plate; the guide straight plate is arranged on the diagonal line of the thermal insulation plate, the fourth guide plate and the fifth guide plate are recessed in the middle, and the fourth guide plate and the fifth guide plate are arranged side by side and are arranged between two adjacent guide straight plates.

[0014] Preferably, the inflection points of the fourth guide plate, the fifth guide plate and the straight guide plate are all arc-shaped, and the depths of the fourth guide plate, the fifth guide plate and the straight guide plate are 2 mm to 20 mm.

[0015] Preferably, the battery pack further comprises a thermal insulation component; the thermal insulation component is bonded to the battery pack body, and the thermal insulation component is connected to the thermal insulation sheet.

[0016] Preferably, the material of the thermal insulation component is aerogel.

[0017] Preferably, the thermal insulation sheet is a flat thermal insulation sheet or a sloped thermal insulation sheet.

[0018] Preferably, the material of the flow guide component is mica board.

[0019] Preferably, the plurality of sensors are any combination of temperature sensors, gas pressure sensors, smoke sensors, gas composition detection sensors, and gas flow rate sensors.

[0020] (III) Beneficial effects

[0021] Compared with the prior art, the beneficial effects of the technical solution of the present invention are: the battery pack with the function of detecting thermal runaway signals provided by the present invention, when thermal runaway occurs anywhere in the battery pack, can allow the gas with a certain airflow velocity, high temperature, medium pressure, smoke and certain components to be quickly guided to the sensor position along the airflow channel between the guide parts through the guide assembly and multiple sensors provided by the present invention, thereby quickly detecting the thermal runaway signal and reporting the thermal runaway signal as an alarm to the entire vehicle to remind the occupants to evacuate, thereby ensuring the safety of the occupants; by providing a thermal insulation assembly and a thermal insulation sheet, the thermal insulation and fire resistance performance of the battery system can be guaranteed, thereby delaying the heat spread event and effectively providing a guarantee for the safety of the occupants. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of a battery pack with a function of detecting thermal runaway signals provided by the present invention;

[0024] Figure 2 A bottom view of an implementation manner of a flow guide assembly;

[0025] Figure 3 A bottom view of another embodiment of the flow guide assembly;

[0026] Figure 4 It is a cross-sectional schematic diagram of a sloped heat insulation sheet;

[0027] Figure 5 It is a schematic cross-sectional view of a flat thermal insulation sheet.

[0028] [Description of Reference Numerals]

[0029] 1: battery pack body; 2: guide assembly; 21: thermal insulation sheet; 22: guide piece; 221: first guide sheet; 222: second guide sheet; 223: third guide sheet; 224: straight guide sheet; 225: fourth guide sheet; 226: fifth guide sheet; 3: thermal insulation assembly; 4: sensor; 41: temperature sensor; 42: smoke sensor; 43: gas pressure sensor. DETAILED DESCRIPTION

[0030] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific embodiments in conjunction with the accompanying drawings. Obviously, the described implementation embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] The present invention provides a battery pack with a function of detecting thermal runaway signals, such as Figure 1As shown, it includes: a battery pack with the function of detecting thermal runaway signals includes: a battery pack body 1, a flow guide assembly 2 and a plurality of sensors 4; the flow guide assembly 2 includes a heat insulating sheet 21 and a flow guide 22, the heat insulating sheet 21 and the flow guide 22 are an integrated structure, and the flow guide 22 is arranged at the bottom of the heat insulating sheet 21; the heat insulating sheet 21 is arranged on the battery pack body 1; a plurality of sensors 4 are arranged around the heat insulating sheet 21, wherein at least two of the sensors 4 are arranged at the end of the flow guide 22. By setting the flow guide assembly 2 and the plurality of sensors 4, the gas with a certain airflow velocity, high temperature, medium pressure, smoke and certain components can be quickly guided to the position of the sensor 4 along the flow guide 22, so as to quickly detect the thermal runaway signal and report the thermal runaway signal to the whole vehicle as an alarm information, so as to remind the occupants to evacuate, thereby ensuring the safety of the occupants. Among them, the box 5 of the battery pack can be formed of iron material or aluminum material, and the present invention is mainly applicable to the field of new energy electric vehicles.

[0035] In addition, the battery pack provided in the present invention adopts a soft pack, a square shell, and a cylindrical battery cell, which is composed of modules connected in series. The battery pack is equipped with a BMS module (battery management system) and a battery thermal management system, which can effectively protect the safety of the battery pack. Among them, the main function of the BMS module is to monitor and manage various parameters in the battery pack, including short circuit protection, fault diagnosis and other functions.

[0036] In a preferred embodiment, Figure 2 As shown, the guide member 22 includes a first guide plate 221, a second guide plate 222 and a third guide plate 223. The first guide plate 221, the second guide plate 222 and the third guide plate 223 are all arc-shaped structures symmetrical at both ends and can form air flow channels between each other. The first guide plate 221, the second guide plate 222 and the third guide plate 223 are symmetrically spaced about the diagonal line of the heat insulation plate 21. Figure 2 As shown, the first guide vane 221, the second guide vane 222 and the third guide vane 223 can guide the airflow to the two diagonal corners of the heat insulation sheet 21, so that the airflow can be guided to the position of the sensor 4 along the first guide vane 221, the second guide vane 222 and the third guide vane 223. By providing the first guide vane 221, the second guide vane 222 and the third guide vane 223, when thermal runaway occurs, a gas with a certain airflow velocity, high temperature, medium pressure, smoke and certain components is ejected, and the ejected gas is quickly guided to the position of the sensor 4 along the airflow channel formed between the first guide vane 221, the second guide vane 222 and the third guide vane, and the sensor 4 transmits the data to the control module, thereby quickly detecting the thermal runaway signal and reporting the thermal runaway signal to the whole vehicle as an alarm information, which buys time for evacuating the passengers, thereby ensuring the safety of the passengers.

[0037] like Figure 2As shown, the inflection points of the first guide vane 221, the second guide vane 222, and the third guide vane 223 are all arc-shaped, so that the airflow does not stay at the inflection points, but flows along the arc to the airflow channels on both sides; the depth of the first guide vane 221, the second guide vane 222, and the third guide vane 223 is 2mm to 20mm, preferably 6mm, and can also be freely designed according to the internal height space of the battery pack. By providing the guide component 2, the gas with a certain airflow velocity, high temperature, medium pressure, smoke and certain components can be quickly guided to the position of the sensor 4 along the airflow channel between the first guide vane 221, the second guide vane 222, and the third guide vane 223, thereby quickly detecting the thermal runaway signal. As shown Figure 2 As shown, the guide piece 22 is symmetrically distributed about the diagonal of the heat insulation sheet 21, and the first guide piece 221, the second guide piece 222 and the third guide piece 223 and the heat insulation sheet 21 are an integrated structure, which can be formed by injection molding or hydraulic molding. The shape and depth of the first guide piece 221, the second guide piece 222 and the third guide piece 223 can be set as needed, as long as they can quickly guide the airflow to the position of the sensor 4.

[0038] In another preferred embodiment, Figure 3 As shown, the guide member 22 includes a fourth guide piece 225, a fifth guide piece 226 and a guide straight piece 224; the guide straight piece 224 is arranged on the diagonal line of the heat insulation sheet 21, and two guide straight pieces 224 can be arranged at intervals on each diagonal line. The fourth guide piece 225 and the fifth guide piece 226 are recessed in the middle, and the fourth guide piece 225 and the fifth guide piece 226 are arranged in parallel and arranged between two adjacent guide straight pieces 224. The fourth guide piece 225, the fifth guide piece 226 and the guide straight piece 224 can form an air flow channel to pass the ejected gas, so as to quickly guide the ejected gas to the position of the sensor 4. Among them, the inflection points of the fourth guide piece 225, the fifth guide piece 226 and the guide straight piece 224 are all arc-shaped, and the depth of the fourth guide piece 225, the fifth guide piece 226 and the guide straight piece 224 is 2mm to 20mm, preferably 6mm.

[0039] Among them, Figure 1As shown, the battery pack also includes an insulation component 3; the insulation component 3 is bonded to the battery pack body 1, and the insulation component 3 is connected to the insulation sheet 21. The material of the insulation component 3 can also be aerogel, polyurethane foam, or silicone flame retardant foam and other insulation materials, preferably aerogel. The insulation component 3 can be made of any material that can achieve good insulation effect. The insulation component 3 can be made into a sheet for easy use. Among them, the material of the insulation component 3 is aerogel. Aerogel, also known as dry gel. When most of the solvent is removed from the gel, the liquid content in the gel is much less than the solid content, or the medium filled in the spatial network structure of the gel is gas, and the appearance is solid. This is a dry gel, also called aerogel. The thermal conductivity and refractive index of aerogel are also very low, and it is very strong and durable. Among them, the solid-state thermal conductivity of silicon aerogel is 2 to 3 orders of magnitude lower than that of the corresponding glassy material. Nano-micropores inhibit the contribution of gas molecules to heat conduction. The refractive index of silica aerogel is close to 1, and the ratio of its annihilation coefficients for infrared and visible light is over 100. It can effectively transmit sunlight and block infrared thermal radiation from ambient temperature, making it an ideal transparent thermal insulation material.

[0040] Furthermore, the heat insulation sheet 21 is a flat heat insulation sheet or a slope heat insulation sheet. The heat insulation sheet 21 is preferably a slope heat insulation sheet, such as Figure 5 As shown, the flat-plate heat insulation sheet refers to a heat insulation sheet 21 whose upper and lower surfaces are both flat and is a complete plate-like structure; Figure 4 As shown, the sloped heat insulation sheet refers to the upper surface of the heat insulation sheet 21 whose thickness increases from one diagonal line of the heat insulation sheet 21 to both sides of the diagonal line to form a slope. Figure 2 and Figure 4 The thickness of the heat insulation sheet 21 on the diagonal line perpendicular to the guide direction of the first guide sheet 221 is the smallest, and the thickness of the heat insulation sheet 21 on both sides of the diagonal line increases successively. Figure 3 and Figure 4 ,because Figure 3 In the embodiment, the heat insulating sheet 21 and the guide member 22 are symmetrical structures, so the thickness of the heat insulating sheet 21 on one of the diagonals can be selected to be the smallest, and the thickness of the heat insulating sheet 21 on both sides of the diagonal increases successively. Since the heat insulating sheet 21 and the guide member 22 are an integrated structure, the heat insulating sheet 21 is set to a sloped structure, and the guide member 22 is also inclined accordingly. By setting the heat insulating sheet 21 to a sloped structure, when thermal runaway occurs in the battery pack, the ejected gas can be quickly guided along the inclined air flow channel to the position of the sensor 4 at the end of the guide member 22, so as to quickly obtain a thermal runaway signal and provide alarm information in time.

[0041] The material of the flow guide component 2 is preferably a mica board. The mica board is made of mica paper and organic silicone water, which are bonded, heated, and pressed. The mica content is about 90%, and the organic silicone water content is 10%. The mica board has excellent high-temperature insulation performance, with a maximum temperature resistance of up to 1000°C. It is a very good thermal insulation material and has a good cost-effectiveness among high-temperature insulation materials. The mica board also has excellent electrical insulation performance.

[0042] like Figure 2 and Figure 3 As shown, the battery pack includes a plurality of sensors 4, wherein at least two of the sensors 4 are disposed at the end of the guide member 22, so as to directly detect the signal at the end of the guide member 22, and the plurality of sensors 4 are any combination of a temperature sensor 41, a gas pressure sensor 43, a smoke sensor 42, a gas composition detection sensor, and a gas flow rate sensor, wherein the type of sensor 4 is not limited to the types listed above, and all sensors 4 that can detect thermal runaway signals are within the protection scope of this patent, and the types of sensors 4 and the positions and quantities of sensors 4 can be arbitrarily combined, and any schemes of the combination are within the protection scope of this patent. Depending on the cost or design requirements, the sensors 4 can be arbitrarily combined, and the preferred combination is a combination of a smoke sensor 42 and a temperature sensor 41. The sensor 4 in the present invention is a common sensor 4 on the market. Preferably, as Figure 2 As shown, smoke sensors 42 are arranged at both ends of the guide member 22, a temperature sensor 41 is arranged at the center of the heat insulation sheet 21, and gas pressure sensors 43 are respectively arranged at the remaining two diagonal positions of the heat insulation sheet 21. By arranging multiple different sensors 4 at different positions, information such as gas temperature, pressure, and gas composition can be collected at multiple positions at the same time, so as to quickly detect thermal runaway signals.

[0043] It should be understood that the above description of the specific embodiments of the present invention is only for illustrating the technical route and features of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, but the present invention is not limited to the above specific implementation methods. Any changes or modifications made within the scope of the claims of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack with a function of detecting thermal runaway signals, characterized in that: The battery pack includes: a battery pack body, a flow guide component and a plurality of sensors; a BMS module and a battery thermal management system are arranged in the battery pack body; The guide assembly includes a heat insulation sheet and a guide member, the heat insulation sheet and the guide member are an integrated structure, the guide member is arranged at the bottom of the heat insulation sheet; the heat insulation sheet is arranged on the battery pack body; the heat insulation sheet is a flat heat insulation sheet or a slope heat insulation sheet; the guide member includes a first guide sheet, a second guide sheet and a third guide sheet, the first guide sheet, the second guide sheet and the third guide sheet are all arc structures symmetrical at both ends and can form an air flow channel between each other, and the first guide sheet, the second guide sheet and the third guide sheet are symmetrically spaced about the diagonal line of the heat insulation sheet; A plurality of the sensors are arranged at the periphery of the heat insulation sheet, wherein at least two of the sensors are arranged at the end of the guide member.

2. The battery pack with a function of detecting thermal runaway signals according to claim 1, characterized in that: The inflection points of the first guide plate, the second guide plate, and the third guide plate are all arc-shaped, and the depths of the first guide plate, the second guide plate, and the third guide plate are 2 mm to 20 mm.

3. The battery pack with a function of detecting thermal runaway signals according to claim 1, characterized in that: The guide member includes a fourth guide plate, a fifth guide plate and a guide straight plate; the guide straight plate is arranged on the diagonal line of the thermal insulation plate, the fourth guide plate and the fifth guide plate are recessed in the middle, and the fourth guide plate and the fifth guide plate are arranged in parallel and between two adjacent guide straight plates.

4. The battery pack with a function of detecting thermal runaway signals according to claim 3, characterized in that: The inflection points of the fourth guide plate, the fifth guide plate and the straight guide plate are all arc-shaped, and the depths of the fourth guide plate, the fifth guide plate and the straight guide plate are 2 mm to 20 mm.

5. The battery pack with a thermal runaway signal detection function according to any one of claims 1 to 4, characterized in that: The battery pack further comprises a heat insulation component; the heat insulation component is bonded to the battery pack body, and the heat insulation component is connected to the heat insulation sheet.

6. The battery pack with a function of detecting thermal runaway signals according to claim 5, characterized in that: The material of the thermal insulation component is aerogel.

7. The battery pack with a thermal runaway signal detection function according to any one of claims 1 to 4, characterized in that: The material of the flow guide component is mica board.

8. The battery pack with a thermal runaway signal detection function according to any one of claims 1 to 4, characterized in that: The multiple sensors are any combination of temperature sensors, gas pressure sensors, smoke sensors, gas composition detection sensors, and gas flow rate sensors.

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