Battery pack thermal diffusion prevention device and method

Abstract

Disclosed is a device and method for preventing thermal diffusion of a battery pack. In the device, at least one temperature sensor is provided on the battery pack to measure its temperature data; a controller is connected to the temperature sensor, and when the temperature data exceeds a predetermined threshold, the controller generates a trigger signal; at least one fire extinguishing agent spraying device is installed above the battery pack and is communicatively connected to the controller, the fire extinguishing agent spraying device mixes powder and sprays based on the trigger signal, the powder bin includes at least two compartments to separately and separately accommodate at least two kinds of powder, the powder reacts and absorbs heat after mixing, the bottom plate is openably provided at the bottom of the powder bin, the mixing bin is located below the bottom plate, the mixing bin is provided with a stirring device for mixing at least two kinds of powder from the powder bin into cooling materials, and the spraying bin is connected to the mixing bin to spray cooling materials toward the battery pack to cool the battery pack. The device effectively prevents and quickly prevents the occurrence of thermal runaway and thermal diffusion of the battery.

Description

Technical Field

[0001] The present invention relates to the field of power battery safety technology, and in particular to a device and method for preventing thermal diffusion of a battery pack. Background Art

[0002] New energy vehicles have become an important part of my country's automobile industry, and even the future development direction. As the core component of new energy vehicles, power batteries have also become the focus of the industry. As the mileage of new energy vehicles continues to increase, the energy density of power batteries is also increasing, and the capacity and volume are constantly expanding. In particular, the widespread use of ternary material batteries has increased the risk of thermal runaway of batteries, posing a great threat to the safety of vehicles and personnel.

[0003] In view of the danger of thermal runaway of power batteries, the industry has increased its research efforts on thermal runaway of batteries and thermal diffusion of battery systems in recent years. The intelligent trigger fire extinguishing device uses a temperature-sensitive material. When the battery thermal runaway occurs, the heat generated by the battery fire is used to deform the nozzle and spray out the fire extinguishing agent. The existing technology also directly injects the fire extinguishing agent into the battery cell and uses aerosols to extinguish the fire. All of them use fire extinguishing agents or aerosols to cover the batteries that have thermal runaway to extinguish the fire and suppress thermal runaway. However, for batteries that have thermal runaway, especially lithium-ion batteries, the reaction is rapid and violent, and oxygen is produced during the reaction. Therefore, these methods are not very effective and operable.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0005] The object of the present invention is to provide a battery pack thermal diffusion prevention device and method, which can accurately and effectively predict the thermal runaway of the battery pack and prevent the occurrence of thermal runaway and thermal diffusion.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A battery pack heat diffusion prevention device of the present invention comprises:

[0008] A battery pack comprising a plurality of battery modules,

[0009] A plurality of temperature sensors are provided in the battery module to measure the temperature data of the battery module;

[0010] A controller connected to the temperature sensor, wherein when the temperature data exceeds a predetermined threshold, the controller generates a trigger signal;

[0011] A plurality of fire extinguishing agent spraying devices, the fire extinguishing agent spraying devices are installed above the battery module and are communicatively connected to the controller, the fire extinguishing agent spraying devices mix powder and spray based on a trigger signal, and the fire extinguishing agent spraying devices include:

[0012] The powder bin comprises at least two compartments for separately accommodating at least two kinds of powders, which react and absorb heat after mixing.

[0013] A bottom plate is openably and closably arranged at the bottom of the powder bin,

[0014] A mixing bin is located below the bottom plate and is provided with a stirring device for mixing at least two powder materials from the powder material bin into cooling materials.

[0015] A spray chamber is connected to the mixing chamber to spray the cooling material toward the battery module to cool the battery module.

[0016] In the battery pack thermal diffusion prevention device, the at least two powders include ammonium chloride and barium hydroxide octahydrate, disodium hydrogen phosphate dodecahydrate and ammonium nitrate, or sodium carbonate decahydrate and ammonium nitrate.

[0017] In the battery pack thermal diffusion prevention device, the predetermined threshold is greater than the upper limit of the single cell temperature for normal operation of the battery pack and is less than the thermal runaway trigger temperature.

[0018] In the battery pack heat diffusion prevention device, the temperature sensor should be installed at the battery module explosion relief valve.

[0019] In the battery pack heat diffusion prevention device, the battery pack heat diffusion prevention device further includes:

[0020] A temperature acquisition device is connected to the temperature sensor to receive the temperature data of each battery module in the battery pack and convert it into a digital signal that can be recognized by the controller.

[0021] A signal generator is connected to the controller and converts the trigger signal into a control signal and sends it to the fire extinguishing agent spraying device. The temperature acquisition device, the controller and the signal generator constitute a control system.

[0022] In the battery pack thermal diffusion prevention device, the control system is integrated into the BMS of the battery system or the control system is an independent system.

[0023] In the battery pack heat diffusion prevention device, the fire extinguishing agent spraying device is connected to the control system via a data line to receive a control signal. The fire extinguishing agent spraying device opens the bottom plate based on the control signal so that the powder in the powder bin falls into the mixing bin. The stirring device stirs the powder to form a cooling material, and the spraying bin sprays the cooling material toward the battery module.

[0024] In the battery pack heat diffusion prevention device, the spray chamber includes an acceleration chamber for accelerating the cooling of the material and a trumpet mouth for guiding the cooling material to spray toward the battery pack.

[0025] In the battery pack heat diffusion prevention device, the acceleration chamber includes an axial flow fan.

[0026] The prevention method of the battery pack thermal diffusion prevention device comprises the following steps:

[0027] The temperature sensor measures the temperature data of the battery module, and when the temperature data exceeds a predetermined threshold, the controller generates a trigger signal;

[0028] Based on the trigger signal, the bottom plate is opened so that the powder in the powder bin falls into the mixing bin;

[0029] The stirring device stirs the powder to form a cooling material, and the spraying chamber sprays the cooling material toward the battery module to cool the battery module.

[0030] In the above technical scheme, a battery pack thermal diffusion prevention device provided by the present invention has the following beneficial effects: Compared with the prior art, when the temperature of a battery module in the battery pack reaches the critical value that triggers thermal runaway, whether it is due to overcharging or internal short circuit, as long as the critical value is reached, the control system will send a start signal to the fire extinguishing agent spraying device corresponding to the battery module that has reached the critical value, and then the hatch of the powder bin will be opened, and the powders of different drugs will be sent into the mixing bin to be fully mixed in a short time, and then sprayed from the spraying bin to the corresponding battery or module, so as to quickly cool the module and prevent the occurrence of thermal runaway. If the BMS of the battery pack does not cut off the power supply so that the process cannot be stopped, or the internal short circuit cannot be resolved, indicating that thermal runaway continues to occur, this method can also slow down the occurrence of thermal runaway by freezing the corresponding battery module. At the same time, the spraying device is installed above each module, so when thermal runaway causes thermal diffusion, it can also play a role in slowing down the occurrence of thermal diffusion, leaving enough time for members to escape. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0032] Figure 1 A schematic structural diagram of a battery pack thermal diffusion prevention device provided in an embodiment of the present invention.

[0033] Figure 2A schematic structural diagram of a fire extinguishing agent spraying device of a battery pack thermal diffusion prevention device provided in an embodiment of the present invention.

[0034] Figure 3 It is a structural schematic diagram of a fire extinguishing agent spraying device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0038] In the description of the present invention, it should be understood that the terms center, longitudinal, lateral, length, width, thickness, up, down, front, back, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In addition, the terms first and second are used only for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as first and second may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of multiple is two or more, unless otherwise clearly and specifically defined.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms such as installation, connection, connection, fixing, etc. should be understood in a broad sense, for example, it can be fixed connection, detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present invention, unless otherwise clearly specified and limited, a first feature being above or below a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being above, above, and above a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being below, below, and below a second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0042] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0043] See also Figure 1-3 As shown, in one embodiment, a battery pack heat diffusion prevention device of the present invention includes:

[0044] A battery pack comprising a plurality of battery modules,

[0045] A plurality of temperature sensors are provided in the battery module to measure the temperature data of the battery module;

[0046] A controller 2 connected to the temperature sensor, when the temperature data exceeds a predetermined threshold, the controller 2 generates a trigger signal;

[0047] At least one fire extinguishing agent spraying device 4, which is installed above the battery module and is communicatively connected to the controller 2, the fire extinguishing agent spraying device 4 mixes powder and sprays based on a trigger signal, and the fire extinguishing agent spraying device 4 includes:

[0048] The powder bin 41 includes at least two compartments for separately accommodating at least two kinds of powders, which react and absorb heat after mixing.

[0049] The bottom plate 42 is openably and closably disposed at the bottom of the powder bin 41.

[0050] The mixing bin 43 is located below the bottom plate 42 and is provided with a stirring device 45 for mixing at least two powder materials from the powder material bin 41 into cooling materials.

[0051] A spray chamber is connected to the mixing chamber 43 to spray the cooling material toward the battery pack 1 to cool the battery module.

[0052] In a preferred embodiment of the battery pack thermal diffusion prevention device, the at least two powders include ammonium chloride and barium hydroxide octahydrate, disodium hydrogen phosphate dodecahydrate and ammonium nitrate, or sodium carbonate decahydrate and ammonium nitrate.

[0053] In a preferred embodiment of the battery pack thermal diffusion prevention device, the predetermined threshold is greater than the upper limit of the single cell temperature of the battery pack 1 for normal operation and is less than the thermal runaway trigger temperature.

[0054] In a preferred embodiment of the battery pack heat diffusion prevention device, the temperature sensor should be installed at the battery module explosion relief valve.

[0055] In a preferred embodiment of the battery pack heat diffusion prevention device, the battery pack heat diffusion prevention device further includes:

[0056] A temperature acquisition device is connected to the temperature sensor to receive the temperature data of each battery module in the battery pack 1 and convert it into a digital signal that can be recognized by the controller 2.

[0057] The signal generator is connected to the controller 2 and converts the trigger signal into a control signal and sends it to the fire extinguishing agent spraying device 4. The temperature acquisition device, the controller 2 and the signal generator constitute a control system.

[0058] In a preferred embodiment of the battery pack thermal diffusion prevention device, the control system is integrated into the BMS of the battery system or is an independent system.

[0059] In a preferred embodiment of the battery pack heat diffusion prevention device, the fire extinguishing agent spraying device 4 is connected to the control system via a data line 3 to receive a control signal. The fire extinguishing agent spraying device 4 opens the bottom plate 42 based on the control signal so that the powder in the powder bin 41 falls into the mixing bin 43. The stirring device 45 stirs the powder to form a cooling material, and the spraying bin sprays the cooling material toward the battery module.

[0060] In a preferred embodiment of the battery pack heat diffusion prevention device, the spray chamber includes an acceleration chamber for accelerating the cooling of the material and a bell mouth 44 for guiding the cooling material to spray toward the battery pack 1.

[0061] In a preferred embodiment of the battery pack heat diffusion prevention device, the acceleration chamber includes an axial flow fan.

[0062] In one embodiment, the multiple battery modules in the battery pack 1 are arranged in an array, and the battery modules correspond to the temperature sensors and the fire extinguishing agent spraying devices 4 one by one.

[0063] In one embodiment, an upper temperature limit is set in the control system. When the temperature of the cell or module in the battery pack 1 exceeds the upper temperature limit, the control system issues an alarm and triggers the fire extinguishing agent spraying device 4 to prevent further thermal runaway or thermal diffusion. The upper temperature limit can be set according to the characteristics of the battery pack 1. Its value should be greater than the upper temperature limit of the cell for normal operation of the battery pack 1 and less than the thermal runaway trigger temperature. The temperature sensor should be installed on the large surface of the battery cell or the explosion relief valve of the battery module.

[0064] In one embodiment, the control system is composed of a controller 2, a temperature acquisition device and a signal generator. The controller 2 is used to process the comparison results between the temperature of each cell and module and the set temperature upper limit, and then judge the battery or module that is expected to have thermal runaway according to the results, and send a working signal to the fire extinguishing agent spraying device 4 to prevent or slow down the occurrence of thermal runaway. The temperature acquisition device is used to receive the temperature signal of each battery or module and convert it into a digital signal that can be recognized by the controller 2. The signal generator converts the trigger command issued by the controller 2 into a control signal and sends it to the fire extinguishing agent spraying device 4 at the battery position where thermal runaway is about to occur. The control system is installed inside the battery pack 1, and can be combined with the BMS of the battery system, built based on the BMS, or built separately. If the control system is combined with the BMS of the battery pack 1, it is necessary to add a temperature comparison program and a signal generator to the BMS, and the feedback of the temperature of the battery cell or module is also completed by the BMS of the battery pack 1. If the control system is installed separately inside the battery pack 1 and works independently, it is necessary to set up the controller 2, the temperature acquisition device and the signal generator separately.

[0065] The temperature of the battery cell and module can be collected by sensors arranged on the battery cell or module and uploaded to the temperature collection device, and the temperature sensor can be but not limited to thermocouples, thermistors, etc. After receiving the trigger signal of the control system, the fire extinguishing agent spraying device 4 immediately mixes several powders and then sprays them onto the battery that is about to thermally run away. The powders will react immediately after mixing, absorbing a large amount of heat, cooling the battery or even freezing it, so as to prevent thermal runaway from occurring. The fire extinguishing agent spraying device 4 is composed of three parts: a powder bin 41, a mixing bin 43 and a spraying bin. Furthermore, the fire extinguishing agent spraying device 4 is installed above each battery or module in the battery pack 1 to ensure that each battery or module can be monitored and protected. The powder bin 41 is composed of a plurality of isolated compartments, each of which stores an ultra-fine powdered medicine. Furthermore, an openable bottom plate 42 is installed at the bottom of the powder bin 41, and its switch mechanism can be but not limited to a micro motor, a cylinder, a solenoid valve, etc., and the switch signal comes from the signal generator of the control system. Furthermore, the bottom plate 42 can be opened in a manner that is but not limited to a pull-out type, a foldable type, etc.

[0066] The powder is a substance that can react quickly and absorb heat after two or more kinds of mixtures. The combination can be but not limited to ammonium chloride and barium hydroxide octahydrate, disodium hydrogen phosphate dodecahydrate and ammonium nitrate, sodium carbonate decahydrate and ammonium nitrate, etc. The mixing bin 43 is located below the powder bin 41, and has a built-in stirring device 45, which can mix the medicines dropped from the powder bin 41 in a short time. The stirring device 45 can be but not limited to stirring paddles, air flow stirring, magnetic stirring, etc. The spray bin is used to spray the mixed powder onto the module that is about to have thermal runaway, and its structure is composed of an acceleration bin and a bell mouth 44. The acceleration bin provides an initial velocity for the mixed powder so that the powder can be evenly sprayed onto the battery or module that is about to have thermal runaway. Further, the acceleration method of the acceleration bin can be but not limited to a positive axial flow fan or air flow guide. The structure of the bell mouth 44 should be matched with the battery or module, and a guide plate is installed inside the bell mouth 44 to control the flow direction of the powder. Furthermore, the acceleration chamber and the mixing chamber are integrated together.

[0067] The prevention method of the battery pack thermal diffusion prevention device comprises the following steps:

[0068] The temperature sensor measures the temperature data of the battery pack 1. When the temperature data exceeds a predetermined threshold, the controller 2 generates a trigger signal;

[0069] Based on the trigger signal, the bottom plate 42 is opened so that the powder in the powder bin 41 falls into the mixing bin 43;

[0070] The stirring device 45 stirs the powder to form a cooling material, and the spray chamber sprays the cooling material toward the battery or module to cool the battery module.

[0071] Finally, it should be noted that the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present application.

[0072] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A battery pack thermal diffusion prevention device, characterized in that: It includes: A battery pack comprising a plurality of battery modules, A plurality of temperature sensors are provided in the battery module to measure the temperature data of the battery module; A controller connected to the temperature sensor, wherein when the temperature data exceeds a predetermined threshold, the controller generates a trigger signal; A plurality of fire extinguishing agent spraying devices, the fire extinguishing agent spraying devices are installed above the battery module and are communicatively connected to the controller, the fire extinguishing agent spraying devices mix powder and spray based on a trigger signal, and the fire extinguishing agent spraying devices include: The powder bin comprises at least two compartments for separately accommodating at least two kinds of powders, which react and absorb heat after mixing. A bottom plate is openably and closably arranged at the bottom of the powder bin, A mixing bin is located below the bottom plate and is provided with a stirring device for mixing at least two powder materials from the powder material bin into cooling materials. a spray chamber connected to the mixing chamber to spray the cooling material toward the battery module to cool the battery module; The battery pack heat diffusion prevention device also includes: A temperature acquisition device, which is connected to the temperature sensor to receive the temperature data of each battery module in the battery pack and convert it into a digital signal that can be recognized by the controller; A signal generator connected to the controller, converting the trigger signal into a control signal and sending it to the fire extinguishing agent spraying device, the temperature acquisition device, the controller and the signal generator constitute a control system, the at least two powders include ammonium chloride and barium hydroxide octahydrate, disodium hydrogen phosphate dodecahydrate and ammonium nitrate, or sodium carbonate decahydrate and ammonium nitrate, the spraying chamber includes an acceleration chamber for accelerating the cooling of the material and a bell mouth for guiding the cooling material to spray toward the battery pack, the acceleration chamber provides an initial velocity for the mixed powder so as to evenly spray the powder onto the battery module that is about to thermally runaway, the acceleration chamber includes an axial flow fan, and a guide plate is installed inside the bell mouth to control the flow direction of the powder; Among them, the fire extinguishing agent spraying device is connected to the control system via a data line to receive a control signal. The fire extinguishing agent spraying device opens the bottom plate based on the control signal so that the powder in the powder bin falls into the mixing bin. The stirring device stirs the powder to form a cooling material, and the spraying bin sprays the cooling material toward the battery module.

2. A battery pack thermal diffusion prevention device according to claim 1, characterized in that: The predetermined threshold is greater than the upper limit of the single cell temperature for normal operation of the battery pack and is less than the thermal runaway triggering temperature.

3. A battery pack thermal diffusion prevention device according to claim 1, characterized in that: The temperature sensor should be installed at the battery module explosion relief valve.

4. A battery pack thermal diffusion prevention device according to claim 1, characterized in that: The control system is integrated into the BMS of the battery system or the control system is an independent system.

5. A method for preventing thermal diffusion of a battery pack according to any one of claims 1 to 4, characterized in that: It includes the following steps, The temperature sensor measures the temperature data of the battery module, and when the temperature data exceeds a predetermined threshold, the controller generates a trigger signal; Based on the trigger signal, the bottom plate is opened so that the powder in the powder bin falls into the mixing bin; The stirring device stirs the powder to form a cooling material, and the spraying chamber sprays the cooling material toward the battery module to cool the battery module.

Images