Battery protection plate integrated with combustible gas regulation and control, preparation method of battery protection plate and battery module

Abstract

The invention relates to the technical field of batteries, and provides a battery protection plate integrated with combustible gas regulation and control, a preparation method thereof and a battery module, and the battery protection plate integrated with combustible gas regulation and control comprises a porous heat insulation base material; the phase change hydrogel is adsorbed in the porous structure of the porous heat insulation base material; the aerogenesis flame retardant layer is arranged on the surface of at least one side of the porous heat insulation base material; and the packaging film is arranged on the outer sides of the aerogenesis flame retardant layer and the porous heat insulation base material and is used for packaging the porous heat insulation base material and the aerogenesis flame retardant layer. The battery protection plate integrated with combustible gas regulation and control can uniformly heat under the normal working condition of the battery, so that local overheating in the battery is avoided; when the battery is in thermal runaway, the temperature of the battery can be reduced and the detonation risk can be reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery protection plate with integrated combustible gas regulation, a preparation method thereof, and a battery module. Background Art

[0002] Lithium-ion batteries are green and efficient energy storage devices, but they have poor thermal stability and are prone to thermal runaway under abuse conditions. In actual engineering, lithium-ion batteries are used in groups. The thermal runaway of a certain battery cell will spread to adjacent batteries by heat spread or fire spread, and finally cause the entire battery system to catch fire and explode. At present, the thermal protection materials used in battery modules mainly include aerogels and ceramic fibers. Although they have extremely low thermal conductivity and can reduce the vicious transfer of heat in the battery module, they will also cause localized accumulation of heat during normal battery operation, reducing the operating efficiency of the thermal management system. In addition, the battery pack can usually be considered as a confined space, and a large amount of flammable gases such as H2, CH4 and CO will be released during the thermal runaway of the battery. The flammable gases will cause thermal runaway to be transmitted in the form of fire spread, greatly increasing the risk of explosion of the system. Therefore, how to ensure that the battery system can operate efficiently and safely has become a technical problem that urgently needs to be solved. Summary of the invention

[0003] Based on this, an embodiment of the present application provides a battery protection plate with integrated combustible gas regulation that avoids local heat accumulation and has high safety, a preparation method thereof, and a battery module.

[0004] In a first aspect, the present application provides a battery protection plate with integrated combustible gas regulation, the battery protection plate with integrated combustible gas regulation comprising:

[0005] Porous thermal insulation substrate;

[0006] A phase-change hydrogel adsorbed in the pore structure of the porous thermal insulation substrate;

[0007] A gas-generating flame retardant layer is disposed on at least one side surface of the porous heat-insulating substrate; and

[0008] A packaging film is disposed on the outer sides of the gas-generating flame retardant layer and the porous thermal insulation substrate, and is used for packaging the porous thermal insulation substrate and the gas-generating flame retardant layer.

[0009] In some embodiments, the material of the gas-generating flame retardant layer includes at least one of sodium bicarbonate, sodium carbonate, ammonium bicarbonate, and ammonium carbonate.

[0010] In some embodiments, the thickness of the gas-generating flame retardant layer is 1 mm to 2 mm.

[0011] In some embodiments, a dehydration-type flame retardant is also adsorbed in the pore structure of the porous thermal insulation substrate.

[0012] In some embodiments, the volume average particle size Dv50 of the dehydration-type flame retardant is 1 nm to 100 nm.

[0013] In some embodiments, the mass ratio of the dehydration-type flame retardant to the porous thermal insulation substrate is 1:(1-2).

[0014] In some embodiments, the dehydration-type flame retardant includes at least one of aluminum hydroxide, magnesium hydroxide, and red phosphorus.

[0015] In some embodiments, the decomposition temperature of the dehydration type flame retardant is 200°C to 500°C.

[0016] In some embodiments, the phase change hydrogel includes at least one of sodium alginate, polyacrylamide, sodium polyacrylate, and calcium alginate.

[0017] In some embodiments, the mass ratio of the phase change hydrogel to the porous thermal insulation substrate is (8-10):1.

[0018] In some embodiments, the thermal conductivity of the porous thermal insulation substrate is 0.035 W / (m / K) to 0.040 W / (m / K).

[0019] In some embodiments, the porous thermal insulation substrate has a thickness of 1 mm to 3 mm.

[0020] In some embodiments, the average diameter of the pore structure in the porous thermal insulation substrate is 100 μm to 500 μm, and the porosity is 90% to 95%.

[0021] In some embodiments, the material of the porous thermal insulation substrate includes ceramic fibers.

[0022] Optionally, the average diameter of the ceramic fibers is 500 nm to 1000 nm.

[0023] Optionally, the material of the porous thermal insulation substrate includes at least one of silica fiber, alumina fiber, zirconium oxide fiber, silicon aluminum ceramic fiber, boron silicon ceramic fiber, boron aluminum silicon ceramic fiber and zirconium aluminum silicon ceramic fiber.

[0024] In some embodiments, the gas generation temperature of the gas generation flame retardant layer is 110°C to 200°C.

[0025] In some embodiments, the phase change temperature of the phase change hydrogel is 90°C to 110°C.

[0026] In some embodiments, the encapsulation film includes a first encapsulation layer and a second encapsulation layer, and the edges of the first encapsulation layer and the second encapsulation layer are respectively provided with an adhesive layer to bond the first encapsulation layer and the second encapsulation layer to form a receiving space, and the porous thermal insulation substrate and the gas-generating flame retardant layer are encapsulated in the receiving space.

[0027] In some embodiments, the packaging film includes at least one of an aluminum-plastic film, a polyimide film, and a nylon film.

[0028] In a second aspect, the present application provides a method for preparing a battery protection plate with integrated combustible gas regulation as described in the first aspect, the method for preparing a battery protection plate with integrated combustible gas regulation comprising:

[0029] Adsorbing the phase change hydrogel into the pore structure of the porous thermal insulation substrate;

[0030] The gas-generating flame retardant layer is formed on at least one side of the porous heat-insulating substrate, and the porous heat-insulating substrate and the gas-generating flame retardant layer are encapsulated by the encapsulation film to obtain the battery protection plate with integrated combustible gas regulation.

[0031] In a third aspect, the present application provides a battery module, comprising an outer shell, at least two single cells and at least one battery protection plate with integrated combustible gas regulation as described in the first aspect, wherein the single cells are spaced apart in the outer shell, and the battery protection plate with integrated combustible gas regulation is disposed between two adjacent single cells.

[0032] Compared with the traditional technology, this application has at least the following beneficial effects:

[0033] The battery protection plate with integrated combustible gas regulation in the present application uses a porous insulation substrate adsorbed with phase change hydrogel as the main body. During the normal operation of the battery, due to the excellent thermal conductivity of the phase change hydrogel, a stable and continuous heat conduction channel can be formed in the porous insulation substrate, which plays a good role in temperature control and temperature equalization. When the battery temperature exceeds the normal operating temperature, the phase change hydrogel can absorb heat and vaporize, effectively reducing the peak temperature of the battery cell during thermal runaway; when the phase change hydrogel is completely vaporized, the porous insulation substrate can achieve thermal insulation between the battery cells and reduce the heat transfer of the thermal runaway battery cell. At the same time, the gas-generating flame retardant layer can decompose and release inert gas, dilute the combustible gas released by the battery cell, and consume free radicals such as H· and OH·. The battery protection plate with integrated combustible gas regulation in the present application has the functions of temperature equalization, heat insulation and gas regulation, which can effectively reduce the risk of explosion in the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A schematic cross-sectional view of a battery protection plate with integrated combustible gas regulation provided in one embodiment of the present application;

[0035] Figure 2 A schematic diagram of the internal structure of a battery module provided in one embodiment of the present application;

[0036] Figure 3 is the DSC curve of the flame retardant phase change hydrogel in Example 1 of the present application;

[0037] Figure 4 This is the STA-MS curve of sodium bicarbonate in Example 1 of the present application.

[0038] Among them, 10-battery protection plate with integrated combustible gas control; 11-porous thermal insulation substrate; 12-gas-generating flame retardant layer; 13-packaging film; 20-single battery. DETAILED DESCRIPTION

[0039] Below in conjunction with the embodiments and examples, the present application is further described in detail. These embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms, and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent form obtained also falls within the protection scope of the present application. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0041] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0042] In this application, the terms "first", "second", etc. in "the first aspect", "the second aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0043] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0044] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0045] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the application purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0046] In traditional technology, thermal insulation pads with low thermal conductivity are used to isolate each battery cell to prevent thermal runaway of a single battery cell from causing thermal runaway of other batteries. However, thermal insulation pads are not conducive to the heat transfer and dissipation of the battery cell, which in turn causes heat accumulation in local batteries, reduces the operating efficiency of the battery thermal management system, and easily causes thermal runaway of the battery cell.

[0047] In a first aspect, the present application provides a battery protection plate with integrated combustible gas regulation, such as Figure 1 As shown, the battery protection plate 10 with integrated combustible gas regulation includes:

[0048] Porous heat-insulating substrate 11;

[0049] Phase change hydrogel, adsorbed in the pore structure of the porous thermal insulation substrate 11;

[0050] A gas-generating flame retardant layer 12 is disposed on at least one side of the porous heat-insulating substrate 11; and

[0051] The packaging film 13 is disposed on the outer sides of the gas-generating flame retardant layer 12 and the porous heat-insulating substrate 11 , and is used for packaging the porous heat-insulating substrate 11 and the gas-generating flame retardant layer 12 .

[0052] The battery protection plate with integrated combustible gas regulation in the present application uses a porous insulation substrate adsorbed with phase change hydrogel as the main body. During the normal operation of the battery, due to the excellent thermal conductivity of the phase change hydrogel, a stable and continuous heat conduction channel can be formed in the porous insulation substrate, which plays a good role in temperature control and temperature equalization. When the battery temperature exceeds the normal operating temperature, the phase change hydrogel can absorb heat and vaporize, effectively reducing the peak temperature of the battery cell during thermal runaway; when the phase change hydrogel is completely vaporized, the porous insulation substrate can achieve thermal insulation between the battery cells and reduce the heat transfer of the thermal runaway battery cell. At the same time, the gas-generating flame retardant layer can decompose and release inert gas, dilute the combustible gas released by the battery cell, and consume free radicals such as H· and OH·. The battery protection plate with integrated combustible gas regulation in the present application has the functions of temperature equalization, heat insulation and gas regulation, which can effectively reduce the risk of explosion in the battery system.

[0053] It is understandable that the encapsulation layer in the present application can release the gas generated by the gas-generating flame retardant into the battery. For example, a vent hole can be provided on the encapsulation layer, or an encapsulation layer material capable of venting gas can be used, or the generated gas can rupture the encapsulation layer.

[0054] It can be understood that the phase change hydrogel in this application refers to a hydrogel with an organic material as a matrix and compounded with phase change materials such as water. During the heat absorption process, the water in the phase change hydrogel evaporates. After the water evaporates completely, the organic material will remain in the porous insulating substrate.

[0055] In some embodiments, the material of the gas-generating flame retardant layer includes at least one of sodium bicarbonate, sodium carbonate, ammonium bicarbonate and ammonium carbonate. The present application utilizes a gas-generating flame retardant to release an inert gas when a battery undergoes thermal runaway, so as to reduce the concentration of combustible gases released by thermal runaway of the battery cell, and can consume free radicals such as H· and OH·, effectively reducing the risk of explosion of the battery cell. Taking sodium bicarbonate as an example, it decomposes under heat to produce water and carbon dioxide, which can dilute the combustible gas.

[0056] In some embodiments, the thickness of the gas-generating flame retardant layer is 1 mm to 2 mm, for example, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2.0 mm. The thickness of the gas-generating flame retardant layer is selected as above in the present application to ensure the gas production of the gas-generating flame retardant layer and improve the flame retardant effect.

[0057] In some embodiments, a dehydrating flame retardant is also adsorbed in the pore structure of the porous thermal insulation substrate. It is understandable that the dehydrating flame retardant can remove moisture from the polymer in contact with it during the reaction process. The porous thermal insulation substrate of the present application also adsorbs a dehydrating flame retardant, which can not only further improve the flame retardant effect of the porous thermal insulation substrate, but also the dehydrating flame retardant can dehydrate the organic material in the phase change hydrogel during flame retardancy, thereby converting the organic material in the phase change gel into a solid porous carbon layer, thereby improving the strength of the porous thermal insulation substrate and avoiding severe expansion during thermal runaway of the battery cell and damaging the battery protection plate with integrated combustible gas regulation.

[0058] In some embodiments, the volume average particle size Dv50 of the dehydration-type flame retardant is 1 nm to 100 nm, for example, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm.

[0059] In some embodiments, the mass ratio of the dehydrated flame retardant to the porous thermal insulation substrate is 1: (1-2), for example, 1: 1.0, 1: 1.1, 1: 1.2, 1: 1.3, 1: 1.4, 1: 1.5, 1: 1.6, 1: 1.7, 1: 1.8, 1: 1.9 or 1: 2.0. The present application selects the adsorption amount of the dehydrated flame retardant as above to effectively ensure the flame retardant effect, and ensures that the dehydrated flame retardant reacts with the organic material in the hydrogel to form a porous carbon structure, thereby improving the strength of the porous thermal insulation substrate.

[0060] In some embodiments, the dehydration-type flame retardant includes at least one of aluminum hydroxide, magnesium hydroxide, and red phosphorus.

[0061] In some embodiments, the decomposition temperature of the dehydration type flame retardant is 200°C to 500°C, for example, 200°C, 230°C, 260°C, 290°C, 320°C, 350°C, 380°C, 410°C, 440°C, 470°C or 500°C.

[0062] In some embodiments, the phase change hydrogel includes at least one of sodium alginate, polyacrylamide, sodium polyacrylate and calcium alginate. It is understood that the phase change hydrogel has a high phase change latent heat, which can effectively absorb the heat generated by the thermal runaway of the battery and reduce the peak temperature during the thermal runaway process. For example, the composite phase change hydrogel of sodium alginate and polyacrylamide has a phase change latent heat of 1600 J / g~2000.

[0063] In some embodiments, the mass ratio of the phase change hydrogel to the porous thermal insulation substrate is (8-10):1, for example, 8.0:1, 8.2:1, 8.4:1, 8.6:1, 8.8:1, 9.0:1, 9.2:1, 9.4:1, 9.6:1, 9.8:1 or 10.0:1.

[0064] In some embodiments, the thermal conductivity of the porous insulating substrate is 0.035 W / (m / K) to 0.040 W / (m / K), for example, it can be 0.035 W / (m / K), 0.036 W / (m / K), 0.037 W / (m / K), 0.038 W / (m / K), 0.039 W / (m / K) or 0.040 W / (m / K).

[0065] In some embodiments, the thickness of the porous thermal insulation substrate is 1 mm to 3 mm, for example, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm or 3.0 mm.

[0066] In some embodiments, the average diameter of the pore structure in the porous thermal insulation substrate is 100 μm to 500 μm, and the porosity is 90% to 95%. The present application selects the pore structure and porosity of the porous thermal insulation substrate as above to improve the uniform temperature and thermal insulation effect of the battery protection plate with integrated combustible gas regulation.

[0067] In some embodiments, the material of the porous thermal insulation substrate includes ceramic fibers.

[0068] Optionally, the average diameter of the ceramic fibers is 500 nm to 1000 nm.

[0069] Optionally, the material of the porous thermal insulation substrate includes at least one of silica fiber, alumina fiber, zirconium oxide fiber, silicon aluminum ceramic fiber, boron silicon ceramic fiber, boron aluminum silicon ceramic fiber and zirconium aluminum silicon ceramic fiber.

[0070] In some embodiments, the gas generation temperature of the gas generation flame retardant layer is 110°C to 200°C, for example, it can be 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C.

[0071] In some embodiments, the phase change temperature of the phase change hydrogel is 90°C to 110°C, for example, it can be 90°C, 92°C, 94°C, 95°C, 96°C, 98°C, 100°C, 102°C, 104°C, 105°C, 106°C, 108°C or 110°C.

[0072] The gas generation temperature of the gas generation flame retardant layer and the phase change temperature of the phase change hydrogel selected in the present application can correspond to the thermal runaway process of the battery and effectively inhibit the spread of thermal runaway of the battery.

[0073] In some embodiments, the packaging film includes a first packaging layer and a second packaging layer, and the edges of the first packaging layer and the second packaging layer are respectively provided with adhesive layers to bond the first packaging layer and the second packaging layer to form a receiving space, and the porous thermal insulation substrate and the gas-generating flame retardant layer are encapsulated in the receiving space. The present application uses the first packaging layer, the second packaging layer and the adhesive layer to encapsulate the porous thermal insulation substrate and the gas-generating flame retardant layer. When the phase change hydrogel is gasified and the gas-generating flame retardant is producing gas, the adhesive connection between the first packaging layer and the second packaging layer can be opened, so that the gas generated by the gas-generating flame retardant enters the battery to dilute and consume the combustible gas.

[0074] In some embodiments, the packaging film includes at least one of an aluminum-plastic film, a polyimide film, and a nylon film.

[0075] The second aspect of the present application provides a method for preparing a battery protection plate with integrated combustible gas regulation as described in the first aspect, and the method for preparing a battery protection plate with integrated combustible gas regulation comprises:

[0076] Adsorbing the phase change hydrogel into the pore structure of the porous thermal insulation substrate;

[0077] The gas-generating flame retardant layer is formed on at least one side of the porous heat-insulating substrate, and the porous heat-insulating substrate and the gas-generating flame retardant layer are encapsulated by the encapsulation film to obtain the battery protection plate with integrated combustible gas regulation.

[0078] In some embodiments, the porous heat-insulating substrate further contains a flame retardant, and the preparation method includes:

[0079] After mixing the phase change hydrogel and the flame retardant, the mixture is adsorbed into the porous thermal insulation substrate; or,

[0080] The phase change hydrogel and the flame retardant are independently adsorbed into the porous thermal insulation substrate.

[0081] The third aspect of the present application provides a battery module, such as Figure 2As shown, the battery module includes an outer shell (not shown in the figure), at least two single cells 20 and at least one battery protection plate 10 with integrated combustible gas regulation as described in the first aspect, the single cells 20 are arranged at intervals in the outer shell, and the battery protection plate 10 with integrated combustible gas regulation is arranged between two adjacent single cells 20.

[0082] It is understandable that the present application does not impose any specific requirements or restrictions on the type of single battery, and the type can be adjusted according to actual use requirements. For example, the single battery can be a lithium-ion battery.

[0083] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0084] Example 1

[0085] A porous heat-insulating substrate with a thickness of 2 mm is provided, the porosity of which is 90%, the average diameter of the pore structure is 300 μm, and the material is aluminum silicate ceramic fiber with an average diameter of 800 nm;

[0086] The flame-retardant phase-change hydrogel is obtained by mixing a phase-change hydrogel (specifically polyacrylamide hydrogel) and a dehydration-type flame retardant (specifically aluminum hydroxide). Figure 3 The DSC curve of the flame-retardant phase-change hydrogel has a phase-change latent heat of about 1700 J / g. The phase-change hydrogel and the dehydrated flame retardant are adsorbed into the porous thermal insulation substrate by in-situ polymerization. The mass ratio of the dehydrated flame retardant to the porous thermal insulation substrate is 1:1, and the mass ratio of the phase-change hydrogel to the porous thermal insulation substrate is 9:1.

[0087] Sodium bicarbonate was coated on both sides of the porous heat-insulating substrate adsorbed with the phase-change hydrogel and the dehydration-type flame retardant to form a gas-generating flame retardant layer with a thickness of 1.5 mm. Figure 4 is the STA-MS curve of sodium bicarbonate;

[0088] Then, the first packaging layer, the second packaging layer and the adhesive layer are used for packaging to obtain the battery protection plate with integrated combustible gas regulation. The first packaging layer and the second packaging layer are both aluminum-plastic films with a thickness of 100 μm, and the adhesive layer is a polyurethane adhesive layer with a thickness of 10 μm.

[0089] Comparative Example 1

[0090] A porous heat-insulating substrate with a thickness of 2 mm is provided, the porosity of which is 90%, the average diameter of the pore structure is 100 μm, and the material is aluminum silicate ceramic fiber with an average diameter of 800 nm;

[0091] Then, the first packaging layer, the second packaging layer and the adhesive layer are used for packaging to obtain the battery protection plate with integrated combustible gas regulation. The first packaging layer and the second packaging layer are both aluminum-plastic films with a thickness of 100 μm, and the adhesive layer is a polyurethane adhesive layer with a thickness of 10 μm.

[0092] The length and width of the battery protection plate with integrated combustible gas regulation prepared in the above Example 1 and Comparative Example 1 are adjusted to 210 mm × 130 mm, and assembled with battery cells and housings to form a battery module, wherein the battery cells are specifically 100Ah lithium iron phosphate batteries, and the above-mentioned battery protection plate with integrated combustible gas regulation is arranged between two adjacent battery cells. A battery module without an integrated combustible gas regulation battery protection plate is provided as a blank example.

[0093] The battery module is subjected to a performance test, and the test method includes:

[0094] Battery module explosion test: The battery module is placed in a constant volume container and a heating plate is used to trigger thermal runaway. The constant volume container can seal and collect the gas generated by the thermal runaway of the battery cell (using the battery thermal runaway ejecta capture device provided by CN117191495A for collection). The gas collected by the device is taken out with a sealed air bag, and the gas composition is detected by a gas chromatograph. Table 1 shows the gas volume composition of Example 1 and the blank example, and the explosion limit of the mixed gas is calculated. The calculation method is as follows:

[0095]

[0096] Where: L m is the explosion limit of combustible gas mixture; L i is the explosion limit of a certain flammable gas; V i is the volume fraction of a certain combustible gas, ∑V i =100%.

[0097]

[0098] Where: L N is the explosion limit of the mixed gas; L m is the explosion limit of combustible gas mixture; B is the volume fraction of inert gas.

[0099] Table 1

[0100]

[0101] Among them, the explosion limit of Example 1 is 7.52%, and the explosion limit of the blank example is 4.76%. After the battery protection plate with integrated combustible gas control is set, the lower limit of the combustion and explosion of the battery thermal runaway gas production is increased by 57.98%.

[0102] Furthermore, the explosion limit results of the above embodiments and comparative examples are shown in Table 2.

[0103] Thermal runaway diffusion test: A battery in the above battery module is subjected to a needle puncture test to cause thermal runaway, and the temperature and voltage of the adjacent battery are detected. If the temperature and voltage of the adjacent battery reach the thermal runaway standard, thermal runaway diffusion occurs; if the temperature and voltage of the adjacent battery do not reach the thermal runaway standard, thermal runaway diffusion does not occur. The results are shown in Table 2.

[0104] Table 2

[0105]

[0106] From the above table we can see that:

[0107] Compared with Example 1, it can be seen that the battery protection plate with integrated combustible gas regulation in the present application uses a porous insulation substrate adsorbed with phase change hydrogel as the main body. During the normal operation stage of the battery, due to the excellent thermal conductivity of the phase change hydrogel, a stable and continuous heat conduction channel can be formed in the porous insulation substrate, which plays a good role in temperature control and temperature equalization. When the battery temperature exceeds the normal operating temperature, the phase change hydrogel can absorb heat and vaporize, effectively reducing the peak temperature during the thermal runaway of the battery cell; when the phase change hydrogel is completely vaporized, the porous insulation substrate can achieve thermal insulation between the battery cells and reduce the heat transfer of the thermal runaway battery cell. At the same time, the gas-generating flame retardant layer can decompose and release inert gas, dilute the combustible gas released by the battery cell, and consume free radicals such as H· and OH·. The battery protection plate with integrated combustible gas regulation in the present application has the functions of temperature equalization, heat insulation and gas regulation, which can effectively reduce the risk of explosion in the battery system. Furthermore, in Comparative Example 1, due to the poor strength of the porous insulation substrate, it is easy to rupture, so there is a further risk of thermal runaway. The porous thermal insulation substrate of the present application also contains a dehydrated flame retardant, which can not only further improve the flame retardant effect of the porous thermal insulation substrate, but also the dehydrated flame retardant can transform the organic material in the phase change hydrogel into a solid porous carbon layer during flame retardancy, thereby improving the strength of the porous thermal insulation substrate and avoiding damage to the battery protection plate with integrated combustible gas regulation due to violent expansion during thermal runaway of the battery cell.

[0108] In summary, the battery protection plate with integrated combustible gas regulation of the present application has the following characteristics: (1) Due to the excellent thermal conductivity of the phase change hydrogel, when it is adsorbed inside the porous insulation substrate, it can form a stable and continuous heat conduction channel inside the porous insulation substrate. When the battery module is operating normally, the battery protection plate with integrated combustible gas regulation can play a good role in temperature control and temperature equalization. (2) When the temperature of the battery cell exceeds the normal operating temperature range (for example, exceeding 90°C), the phase change hydrogel begins to vaporize and absorb heat, which can effectively reduce the peak temperature of the battery cell during thermal runaway. (3) When the water in the phase change hydrogel is completely vaporized, the porous insulation substrate can play a role in reducing heat transfer. In addition, the dehydration-type flame retardant can react with the organic material remaining in the phase change hydrogel inside the porous insulation substrate to form a solid porous carbon layer when it is flame retardant, effectively avoiding the severe expansion stress generated during the thermal runaway process of the battery cell from damaging the battery protection plate with integrated combustible gas regulation. (4) When the temperature of the battery cell exceeds a certain temperature (for example, over 110°C), the battery cell discharges combustible gas through the pressure relief valve, and the gas-generating flame retardant layer begins to decompose and release inert gas, diluting the concentration of combustible gas and consuming free radicals such as H· and OH·, which can effectively reduce the risk of explosion caused by thermal runaway gas generation in the battery cell.

[0109] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A battery protection plate with integrated combustible gas control, characterized in that: The battery protection plate with integrated combustible gas regulation comprises: Porous thermal insulation substrate; A phase-change hydrogel adsorbed in the pore structure of the porous thermal insulation substrate; A gas-generating flame retardant layer is disposed on at least one side surface of the porous heat-insulating substrate; and A packaging film is disposed on the outer sides of the gas-generating flame retardant layer and the porous thermal insulation substrate, and is used for packaging the porous thermal insulation substrate and the gas-generating flame retardant layer.

2. The battery protection plate with integrated combustible gas regulation as claimed in claim 1, characterized in that: The gas-generating flame retardant layer satisfies at least one of the following conditions: (1) The material of the gas-generating flame retardant layer includes at least one of sodium bicarbonate, sodium carbonate, ammonium bicarbonate and ammonium carbonate; (2) The thickness of the gas-generating flame retardant layer is 1 mm to 2 mm.

3. The battery protection plate with integrated combustible gas regulation as claimed in claim 1, characterized in that: The porous heat-insulating substrate also has a dehydration-type flame retardant adsorbed in its pore structure; Optionally, the volume average particle size Dv50 of the dehydration type flame retardant is 1 nm to 100 nm; Optionally, the mass ratio of the dehydration-type flame retardant to the porous thermal insulation substrate is 1:(1-2); Optionally, the dehydration-type flame retardant includes at least one of aluminum hydroxide, magnesium hydroxide and red phosphorus; Optionally, the decomposition temperature of the dehydration type flame retardant is 200°C to 500°C.

4. The battery protection plate with integrated combustible gas regulation as claimed in claim 1, characterized in that: The phase change hydrogel satisfies at least one of the following conditions: (1) The phase change hydrogel comprises at least one of sodium alginate, polyacrylamide, sodium polyacrylate and calcium alginate; (2) The mass ratio of the phase change hydrogel to the porous thermal insulation substrate is (8-10):

1.

5. The battery protection plate with integrated combustible gas regulation as claimed in claim 1, characterized in that: The porous thermal insulation substrate meets at least one of the following conditions: (1) The thermal conductivity of the porous thermal insulation substrate is 0.035W / (m / K)~0.040W / (m / K); (2) The thickness of the porous thermal insulation substrate is 1 mm to 3 mm; (3) The average diameter of the pore structure in the porous thermal insulation substrate is 100 μm to 500 μm, and the porosity is 90% to 95%.

6. The battery protection plate with integrated combustible gas regulation as claimed in claim 1, characterized in that: The material of the porous heat-insulating substrate includes ceramic fibers; Optionally, the average diameter of the ceramic fiber is 500nm~1000nm; Optionally, the material of the porous thermal insulation substrate includes at least one of silica fiber, alumina fiber, zirconium oxide fiber, silicon aluminum ceramic fiber, boron silicon ceramic fiber, boron aluminum silicon ceramic fiber and zirconium aluminum silicon ceramic fiber.

7. The battery protection plate with integrated combustible gas regulation as claimed in claim 1, characterized in that: The battery protection plate with integrated combustible gas regulation meets at least one of the following conditions: (1) The gas generation temperature of the gas generation flame retardant layer is 110°C to 200°C; (2) The phase change temperature of the phase change hydrogel is 90°C~110°C.

8. The battery protection plate with integrated combustible gas control as claimed in any one of claims 1 to 7, characterized in that: The packaging film satisfies at least one of the following conditions: (1) The encapsulation film comprises a first encapsulation layer and a second encapsulation layer, and the edges of the first encapsulation layer and the second encapsulation layer are respectively provided with an adhesive layer to bond the first encapsulation layer and the second encapsulation layer to form a receiving space, and the porous heat-insulating substrate and the gas-generating flame retardant layer are encapsulated in the receiving space; (2) The packaging film includes at least one of an aluminum-plastic film, a polyimide film and a nylon film.

9. A method for preparing a battery protection plate with integrated combustible gas regulation according to any one of claims 1 to 8, characterized in that: The preparation method of the battery protection plate with integrated combustible gas regulation comprises: Adsorbing the phase change hydrogel into the pore structure of the porous thermal insulation substrate; The gas-generating flame retardant layer is formed on at least one side of the porous heat-insulating substrate, and the porous heat-insulating substrate and the gas-generating flame retardant layer are encapsulated by the encapsulation film to obtain the battery protection plate with integrated combustible gas regulation.

10. A battery module, characterized in that: The battery module includes an outer shell, at least two single cells and at least one battery protection plate with integrated combustible gas regulation as described in any one of claims 1 to 8, wherein the single cells are spaced apart in the outer shell, and the battery protection plate with integrated combustible gas regulation is disposed between two adjacent single cells.

Images