Gas inhibition film as well as preparation method and application thereof

Abstract

The invention relates to the technical field of batteries, in particular to a gas inhibition film and a preparation method and application thereof. The gas inhibition film comprises a polymer matrix, and an acid removing agent and an oxygen absorbing agent which are loaded on the polymer matrix, the deacidification agent comprises calcium oxide; the oxygen absorbent comprises at least one of CeO2, nitrogen-doped graphene and a metal organic framework material. The preparation method comprises the following steps: mixing a deacidification agent, an oxygen absorbent and a polymer with a solvent to obtain a spinning solution; and preparing a membrane by adopting an electrostatic spinning method, and performing vacuum drying to obtain the gas inhibition membrane. The gas inhibition film can remove SO2 and O2 generated in the battery in the normal operation process of the battery, so that the service life of the battery is prolonged; the battery can also be used for safety prevention and control, can react with H2O in the air under the condition that the battery is damaged, triggers an alarm by releasing heat, can also absorb H2S generated in the initial stage of leakage, and delays the time of releasing H2S to the outside.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically, to a gas suppression film, its preparation method, and its application. Background Technology

[0002] Solid-state batteries, by using non-flammable solid electrolytes instead of traditional liquid electrolytes, exhibit significant advantages in improving battery thermal stability. Sulfide solid electrolytes, with their high ionic conductivity comparable to liquid electrolytes and their flexibility and ease of molding, have attracted widespread attention in the industry. Sulfide all-solid-state batteries, composed of high-energy-density electrode materials such as lithium metal anodes and high-nickel ternary cathodes, can achieve higher mass / volume energy density, potentially significantly improving the safety and range performance of new energy electric vehicles.

[0003] However, recent research indicates that sulfide solid-state batteries are not absolutely safe, with their main risks stemming from gases and heat, specifically: (1) The problem of high-temperature oxygen release from the high-nickel cathode in the charging state still exists. The sulfide electrolyte will react with the released oxygen, inducing the generation of toxic and harmful SO2 gas. If the battery casing is undamaged, the SO2 generated inside will corrode the copper, aluminum and other metal current collectors, increasing the internal resistance of the battery. According to Joule's law of heat, the increase in internal resistance will cause continuous heat generation, and the accumulation of heat will further aggravate the oxygen release from the cathode. This gas-heat linkage mechanism poses a huge challenge to the performance and safety of the battery.

[0004] (2) When the battery is damaged due to mechanical abuse such as squeezing or puncturing, the sulfide electrolyte in the battery will come into direct contact with the moisture in the air. Even a trace amount of H2O (-40℃ dew point) can attack and destroy the PS bonds of the sulfide electrolyte, generating PO bonds and releasing H2S gas simultaneously. When a person is exposed to an environmental concentration of only 100 ppm H2S for 3-15 minutes, they will experience coughing, eye irritation and loss of smell. After a short exposure to 500 ppm, they will lose consciousness.

[0005] Controlling various gases and heat in sulfide solid-state batteries and timely monitoring and early warning of battery failure are crucial, but effective means in this regard are scarce.

[0006] Patent application CN118684497A utilizes the decomposition of lithium salt at high temperatures to generate an inorganic interface on the surface of the sulfide electrolyte, isolating the sulfide electrolyte from direct contact with the high-nickel ternary cathode, reducing side reactions, and thus reducing SO2 gas generation. However, this method does not mention data on the modified battery, its electrical performance is questionable, and it only achieves single-factor SO2 gas control.

[0007] Patent CN111864205B incorporates sulfonyl ammonium salt into a high-nickel ternary cathode sheet, utilizing the phase transition endothermic effect of the added salt at 40–150°C to reduce the overall heat release of the cathode, thereby lowering thermal safety risks. However, this method introduces additional salt, disrupting the internal conductive network of the electrode sheet and deteriorating electrical performance; it also reduces the proportion of active material in the cathode, resulting in a decrease in battery energy density.

[0008] Patent application CN115986235A discloses a protection method for sulfide solid-state batteries. This method involves placing composite heat insulation pads between battery packs to physically adsorb any overflowing H2S gas and cool the battery cells, preventing the release of H2S that could harm occupants if the battery pack fails. However, this method only addresses the large amount of H2S gas generated by battery failure and fails to control other gases, thus not extending battery life.

[0009] US patent application US20230066390A1 proposes to directly wrap the battery cell or cover the battery pack with a reaction carrier in the form of a flexible sheet, coating, foam or microsphere, and remove H2S through a chemical reaction. The reaction carriers used in this patent are of various forms, but all are located outside the battery.

[0010] In view of this, the present invention is hereby proposed. Summary of the Invention

[0011] The primary objective of this invention is to provide a gas suppression membrane that can remove SO2 and O2 generated in the battery during normal operation, thus extending battery life. It can also be used for safety control; in the event of battery damage, it can react with H2O in the air, releasing heat to trigger an alarm for rapid identification in the early stages of failure. Simultaneously, it can absorb H2S generated from the reaction of H2O with sulfide electrolyte in the early stages of failure, delaying the release of H2S into the environment and providing personnel with sensitive hazard warnings and sufficient time for evacuation and disposal.

[0012] The second objective of this invention is to provide a method for preparing the gas suppression membrane as described above. The method of this invention is simple, easy to implement, and the prepared gas suppression membrane has a large specific surface area, good flexibility, low density, and good gas purification effect.

[0013] A third objective of the present invention is to provide a sulfide solid-state battery, including the gas suppression film as described above.

[0014] The fourth objective of this invention is to provide a safety control system for sulfide solid-state batteries, which can quickly identify and issue warnings in the early stages of battery failure.

[0015] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A gas suppression membrane includes a polymer matrix and an acid remover and an oxygen absorber loaded on the polymer matrix; the acid remover includes calcium oxide; the oxygen absorber includes at least one of CeO2, nitrogen-doped graphene, and metal-organic framework materials.

[0016] Preferably, the metal-organic framework material comprises cobalt tetraphenylporphyrin.

[0017] Preferably, the primary particle size of the acid remover is 20-500 nm.

[0018] Preferably, the primary particle size of the oxygen absorber is 20-600 nm.

[0019] Preferably, the polymer includes at least one of polyvinyl alcohol, polyvinylpyrrolidone, and polyacrylonitrile.

[0020] Preferably, the mass ratio of the polymer, the acid remover, and the oxygen absorber is 1:0.02-0.3:0.02-0.3.

[0021] Preferably, the fiber diameter of the gas suppression membrane is 100-500 nm.

[0022] Preferably, the thickness of the gas suppression film is 5-50 μm.

[0023] Preferably, the contact angle between the gas suppression membrane and water is 5-30°.

[0024] The method for preparing the gas suppression membrane according to any one of the foregoing embodiments includes the following steps: An acid-removing agent, an oxygen absorber, and a polymer are mixed with a solvent to obtain a spinning solution; a film is prepared by electrospinning and then vacuum dried to obtain the gas-suppressing film.

[0025] Preferably, the solvent includes DMF and / or THF.

[0026] Preferably, the mass ratio of the solvent to the polymer is 7-13:1.

[0027] Preferably, the electrospinning injection rate is 0.1-3.0 mL / h, the voltage is 10-30 kV, and the receiving distance is 10-25 cm.

[0028] Preferably, the electrospinning time is 1-10 hours.

[0029] Preferably, the vacuum drying temperature is 60-100℃ and the time is 1-3h.

[0030] A sulfide solid-state battery, comprising the gas suppression film described in any of the foregoing embodiments.

[0031] A safety control system for sulfide solid-state batteries includes a gas suppression film as described in any of the foregoing embodiments; The gas suppression membrane is arranged inside the sulfide solid-state battery cell. A temperature sensor is provided on the gas suppression membrane. The temperature sensor is connected to the battery management system. The battery management system is connected to an alarm. When the temperature rise rate is detected to reach the preset temperature rise rate, the alarm will sound.

[0032] Preferably, the gas suppression film is arranged inside the individual battery cell by being wound around the electrode group or the outer core inside the individual battery cell.

[0033] Preferably, the preset heating rate is 0.5-10℃ / min.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The gas suppression membrane provided by the present invention can remove SO2 and O2 generated in the battery during normal operation, prevent the battery from swelling and bulging, avoid O2-induced thermal runaway reaction, avoid SO2 corrosion of the current collector, thereby avoiding battery performance degradation and heat generation caused by increased internal resistance, and extend battery life.

[0035] (2) The gas suppression membrane provided by the present invention can also be used for safety control of sulfide solid batteries. In the event of mechanical abuse of the battery, resulting in micro-damage, outside air enters the battery. H2O in the air preferentially accumulates on the hydrophilic gas suppression membrane wrapped around the outside of the active cell material, reacts with the deacidifying agent and releases heat. The temperature sensor set in the gas suppression membrane identifies and transmits the information to the BMS system, and the alarm provides an early warning. It can quickly identify and warn of micro-damage to the battery in the early stage of battery failure. In addition, the deacidifying agent can react with H2S generated in the early stage of leakage, delaying the release of H2S to the outside, giving personnel sensitive danger warning and sufficient time for evacuation and disposal. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a sulfide solid-state battery safety control system provided in an embodiment of the present invention; Figure 2 This is a photograph of the gas suppression membrane prepared in Example 1 of the present invention; Figure 3This is a SEM image of the gas suppression membrane prepared in Example 1 of the present invention. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0039] A first aspect of the present invention provides a gas suppression membrane comprising a polymer matrix and an acid remover and an oxygen absorber loaded on the polymer matrix; the acid remover comprises calcium oxide; the oxygen absorber comprises at least one of CeO2, nitrogen-doped graphene, and metal-organic framework materials.

[0040] Existing sulfide solid-state batteries, when the battery casing is undamaged, are prone to generating SO2 and O2 within the battery. SO2 easily corrodes the current collector, leading to increased internal resistance. Increased internal resistance exacerbates heat generation, and the accumulation of heat further induces O2 generation, forming a vicious cycle of "gas generation - increased resistance - heat generation - re-gas generation," posing a severe challenge to the battery's cycle life and thermal safety. Furthermore, when the battery is subjected to mechanical abuse such as squeezing or puncture, causing damage to the casing, the sulfide electrolyte inside the battery will directly come into contact with moisture in the air, thereby reacting to generate highly toxic H2S, threatening personnel safety.

[0041] To address the aforementioned problems, this application provides a gas suppression membrane containing an acid remover and an oxygen absorber. The acid remover can remove SO2 released from the electrode material reaction inside the battery under normal operating conditions, i.e., anhydrous and at room temperature, without producing H2O byproducts, thus preventing internal water generation and electrolyte decomposition. The oxygen absorber can remove O2 released from the electrode material reaction inside the battery under normal operating conditions, i.e., anhydrous and at room temperature. In other words, during normal battery operation, this gas suppression membrane can remove SO2 and O2 generated in the battery, thereby preventing battery swelling and bulging, avoiding O2-induced thermal runaway reactions, preventing SO2 corrosion of the current collector, and thus avoiding battery performance degradation and heat generation caused by increased internal resistance, extending battery life.

[0042] The gas suppression membrane provided by this invention not only has a highly efficient removal and control function for SO2 and O2, but also has a highly efficient removal and control function for H2O and H2S. Therefore, it can also be used for safety control of sulfide solid-state batteries. When the battery is damaged, the acid remover in the gas suppression membrane preferentially reacts with water and releases heat. By monitoring the change in the heating rate, the micro-damage of the battery can be quickly identified and warned. At the same time, it can absorb the H2S generated in the early stage of leakage, delaying its release into the outside world and providing personnel with sensitive danger warnings and sufficient evacuation time.

[0043] The acid remover of this invention contains CaO, which can react efficiently with SO2, resulting in a fast SO2 purification rate. It also reacts violently with water, releasing a large amount of heat, making it suitable for use in safety control systems.

[0044] In some specific embodiments of the present invention, the metal-organic framework material includes cobalt tetraphenylporphyrin (Co-TPP), which has a better oxygen absorption effect than CeO2 and can effectively improve O2 purification efficiency.

[0045] In some specific embodiments of the present invention, the acid remover is a nanoparticle with a primary particle size of 20-500 nm. For example, it can be any single value or any two values ​​from 20 nm, 100 nm, 200 nm, 300 nm, 400 nm, and 500 nm. Preferably, it is 20-250 nm, more preferably 100-150 nm. If the primary particle size is too large, the purification rate of SO2 and H2S will decrease, the heating rate of the reaction with H2O will decrease, and the sensitivity will decrease when used for safety control. If the primary particle size is too small, it is easy to agglomerate and the preparation is difficult.

[0046] In some specific embodiments of the present invention, the oxygen absorber is a nanoparticle with a primary particle size of 20-600 nm. For example, it can be any single value or a range of any two values ​​from 20 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, and 600 nm. Preferably, it is 20-300 nm, more preferably 100-150 nm. If the primary particle size is too large, the oxygen purification rate will decrease. If the primary particle size is too small, it will easily agglomerate and be difficult to prepare.

[0047] In some specific embodiments of the present invention, the polymer matrix material includes at least one of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and polyacrylonitrile (PAN); preferably, it contains at least one of PVA and PVP, for example, any one of the following: PVA, PVP, a combination of PVA and PAN, a combination of PVP and PAN, a combination of PVA, PVP, and PAN, etc., because PVA and PVP are hydrophilic, which can improve the hydrophilicity of the gas suppression membrane, making it easier for H2O in the air to contact the deacidifying agent in the gas suppression membrane, and improving the sensitivity when used for safety control of sulfide solid-state batteries.

[0048] In some specific embodiments of the present invention, the mass ratio of polymer, acid remover, and oxygen absorber in the gas suppression membrane is 1:0.02-0.3:0.02-0.3. For example, it can be any one value or a range of any two values ​​from 1:0.02:0.02, 1:0.1:0.1, 1:0.2:0.2, 1:0.3:0.3, 1:0.1:0.2, 1:0.1:0.3, 1:0.2:0.1, 1:0.3:0.1. If the proportion of acid remover is too small, it is difficult to remove and control SO2 and H2S, and the heating rate when reacting with H2O is small, making it difficult to use for safety control and early warning. If the proportion of oxygen absorber is too small, it is difficult to remove and control O2. If the proportions of acid remover and oxygen absorber are too large, it will cause nanoparticle agglomeration, increase the weight of the gas suppression membrane, and also increase the cost.

[0049] In some specific embodiments of the present invention, the specific surface area of ​​the gas suppression film is 20-1000 m². 2 / g, for example, can be 20m 2 / g、200m 2 / g、500m 2 / g、800m 2 / g, 1000m 2 The range of values ​​for any one point or any two points in / g is preferably 600-900m. 2 / g.

[0050] In some specific embodiments of the present invention, the gas suppression membrane is a nonwoven fiber membrane with a fiber diameter of 100-500 nm. For example, it can be any single value or a range of any two values ​​among 100 nm, 200 nm, 300 nm, 400 nm, and 500 nm.

[0051] In some specific embodiments of the present invention, the density of the gas suppression film is 0.05-0.25 g / cm³. 2 For example, it can be 0.05 g / cm³. 2 0.10 g / cm 20.15g / cm 2 0.20g / cm 2 0.25g / cm 2 The range of values ​​consisting of any one point value or any two point values.

[0052] In some specific embodiments of the present invention, the thickness of the gas suppression film is 5-50 μm, for example, it can be any one value or a range of any two values ​​among 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, and 50 μm.

[0053] In some specific embodiments of the present invention, the contact angle between the gas suppression membrane and water is 5-30°. For example, it can be any single value or a range of any two values ​​from 5°, 8°, 10°, 15°, 20°, 25°, and 30°. The contact angle is the core quantitative method for the hydrophilicity of a material surface. A contact angle less than 90° is considered hydrophilic, and the smaller the angle, the stronger the hydrophilicity.

[0054] The gas suppression membrane provided by this invention is a hydrophilic film with high specific surface area, flexibility, and low density. The high specific surface area allows gas to quickly penetrate into micro- and nano-particles (acid removers and oxygen absorbers) to exert its effect; the flexibility facilitates the winding of the membrane material around the active battery cell material, increasing the effective area; the low density ensures that the membrane material can function efficiently without increasing excessive inactive mass, thus avoiding a decrease in battery energy density; the membrane material is hydrophilic and has a strong adsorption effect on moisture.

[0055] In some specific embodiments of the present invention, for a thickness of 40 μm and an area of ​​50 cm², 2 The gas suppression membrane has an O2 purification rate of 12-30 ppm / min.

[0056] In some specific embodiments of the present invention, for a thickness of 40 μm and an area of ​​50 cm², 2 The gas suppression membrane has an SO2 purification rate of 75-120 ppm / min.

[0057] In some specific embodiments of the present invention, for a thickness of 40 μm and an area of ​​50 cm², 2 The gas suppression membrane has an H2S purification rate of 68-120 ppm / min.

[0058] A second aspect of the present invention provides a method for preparing a gas suppression membrane as described in any of the foregoing embodiments, comprising the following steps: An acid-removing agent, an oxygen absorber, and a polymer are mixed with a solvent to obtain a spinning solution; a film is prepared by electrospinning and then vacuum dried to obtain a gas-suppressing film.

[0059] The method of this invention has a simple preparation process and is easy to implement. The resulting membrane material can remove SO2 and O2 during the normal operation of the battery, thereby extending the battery life. Furthermore, it is sensitive to water and can absorb H2S generated by battery failure, making it suitable for safety control of sulfide solid-state batteries.

[0060] In some specific embodiments of the present invention, the method for preparing the gas suppression membrane specifically includes the following steps: S1. After the deacidifying agent and oxygen absorber are fully dispersed in the solvent by ultrasonication, the polymer powder is slowly added and stirred until it is completely dissolved, forming a uniform, bubble-free viscous solution, which is the spinning solution; S2. Electrospinning: Inject the spinning solution into the syringe, install the needle (blunt metal needle) and fix it on the injection pump, adjust the distance between the needle and the receiving device, turn on the high voltage power supply and the injection pump, and eject the spinning solution at a set rate. As the jet flies toward the receiving device, it is greatly stretched and refined, while the solvent evaporates rapidly. Finally, the solidified nanofibers are deposited on the receiving device in a random or ordered manner to form a nonwoven fiber membrane. The fibers are uniformly loaded with deacidifying agent and oxygen absorber. S3. The obtained membrane material is heated and vacuum dried to remove residual solvent, thus obtaining a gas suppression membrane.

[0061] In some specific embodiments of the present invention, the solvents used include DMF (N,N-dimethylformamide) and / or THF (tetrahydrofuran).

[0062] In some specific embodiments of the present invention, the mass ratio of the solvent to the polymer is 7-13:1. For example, it can be any one value or a range of any two values ​​from 7:1, 9:1, 10:1, 12:1, to 13:1.

[0063] In some specific embodiments of the present invention, the electrospinning injection rate is 0.1-3.0 mL / h, for example, it can be any one value or a range of any two values ​​among 0.1 mL / h, 0.5 mL / h, 1.0 mL / h, 1.5 mL / h, 2.0 mL / h, 2.5 mL / h, and 3.0 mL / h; the voltage is 10-30 kV, for example, it can be any one value or a range of any two values ​​among 10 kV, 15 kV, 20 kV, 25 kV, and 30 kV; the receiving distance is 10-25 cm, for example, it can be any one value or a range of any two values ​​among 10 cm, 15 cm, 20 cm, and 25 cm.

[0064] In some specific embodiments of the present invention, the electrospinning time is 1-10h, for example, it can be any one value or a range of any two values ​​among 1h, 3h, 5h, 8h, and 10h; specifically, it can be adjusted according to the thickness of the spinning film.

[0065] In some specific embodiments of the present invention, the receiving device used is any one of a flat plate receiver, a roller receiver, and a turntable receiver; preferably a roller receiver.

[0066] In some specific embodiments of the present invention, the vacuum drying temperature is 60-100°C, for example, it can be any one value or a range of any two values ​​among 60°C, 70°C, 80°C, 90°C, and 100°C; the time is 1-3 hours, for example, it can be any one value or a range of any two values ​​among 1 hour, 1.5 hours, 2 hours, 2.5 hours, and 3 hours.

[0067] A third aspect of the present invention provides a sulfide solid-state battery, including the gas suppression film described in any of the foregoing embodiments.

[0068] A fourth aspect of the present invention provides a safety control system for sulfide solid-state batteries, comprising the gas suppression film described in any of the foregoing embodiments; A gas suppression membrane is arranged inside the sulfide solid-state battery cell. A temperature sensor is installed on the gas suppression membrane and connected to the battery management system (BMS) so that the temperature signal in the system is transmitted to the BMS system in real time. An external alarm is connected to the battery management system. When the temperature rise rate is detected to reach the preset temperature rise rate, the alarm will sound.

[0069] When the battery casing is slightly cracked, H2O gas from the air enters the battery and preferentially accumulates in the gas suppression membrane arranged inside the cell. It reacts rapidly with the acid remover, and the large amount of heat released by the reaction causes the gas suppression membrane's temperature rise rate to exceed the preset temperature rise rate. This is detected by the temperature sensor and quickly transmitted to the BMS system, which then issues a warning via the car alarm. In addition, the acid remover in the gas suppression membrane can also fully react with the H2S gas released by the electrolyte in the early stage of the battery crack, delaying H2S leakage and giving the occupants sufficient time to evacuate, thus ensuring the safety of the driver and passengers.

[0070] In some specific embodiments of the present invention, when used for safety control of sulfide solid-state batteries, the gas suppression membrane is preferably a hydrophilic membrane. After the battery casing is broken, the hydrophilic membrane material is conducive to enriching H2O in the air, accelerating heat generation, and better realizing early warning.

[0071] In some specific embodiments of the present invention, the gas suppression film is arranged inside the single cell by being wound around the electrode group inside the single cell or outside the core.

[0072] Figure 1 This is a schematic diagram of a sulfide solid-state battery safety control system in some embodiments of the present invention. A gas suppression film is wound around the electrode group inside the single cell. The gas suppression film has a built-in temperature sensor connected to the BMS system. The BMS system is connected to an external alarm.

[0073] In some specific embodiments of the present invention, the preset heating rate is 0.5-10℃ / min. For example, it can be any one value or a range of any two values ​​among 0.5℃ / min, 2℃ / min, 5℃ / min, 8℃ / min, and 10℃ / min; preferably, it is 2-5℃ / min.

[0074] During normal driving, the overall temperature rise rate of the battery pack in an electric vehicle is typically 0.02~0.10℃ / min. The specific value is affected by a combination of battery technology, cooling system, and driving conditions. This range will not interfere with the judgment of the safety and air defense system. The temperature change monitored by the temperature sensor in this application is not the temperature change of the battery cell, but the temperature change of the gas suppression film caused by a specific reaction, which has higher sensitivity.

[0075] The embodiments of the present invention will be described in detail below with reference to specific examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0076] Preparation of cobalt tetraphenylporphyrin (Co-TPP) used in the examples and comparative examples: First, tetraphenylporphyrin was synthesized by the Adler method, that is, using benzaldehyde and pyrrole as raw materials, refluxed at 140°C in propionic acid solvent under nitrogen protection, the reaction solution was poured into cold water to precipitate and then purified; then, tetraphenylporphyrin was refluxed with cobalt chloride (CoCl2·6H2O) in DMF solvent at 120°C for 4 h to complete the cobalt ion introduction reaction, thus obtaining cobalt tetraphenylporphyrin.

[0077] Example 1 Weigh PVA, PAN, CaO nanoparticles (120 nm primary particle size) and Co-TPP (120 nm primary particle size) in a mass ratio of 0.5:0.5:0.2:0.2. First, add CaO and Co-TPP to DMF solvent and sonicate for 5 min. Then, slowly add PVA and PAN powders and stir until completely dissolved to form a uniform, bubble-free, viscous spinning solution. The mass ratio of DMF to the total mass of PVA and PAN polymers is 10:1. Inject the spinning solution into a syringe, install a blunt metal needle, and fix it to the syringe pump. Adjust the distance between the needle and the roller receiver to 20 cm. Set the power supply voltage to 20 kV and simultaneously turn on the high-voltage power supply and the syringe pump to eject the spinning solution at a rate of 2 mL / h. The solidified nanofibers are deposited on the roller receiver in a random or ordered manner for 8 h, forming a layer with a thickness of 40 μm and an area of ​​50 cm². 2 A nonwoven fabric-like fiber membrane was obtained; the fiber membrane was heated at 80°C and vacuum dried for 2 h to obtain a gas suppression membrane.

[0078] The resulting gas suppression membrane, such as Figure 2 As shown in the image (a physical picture of multiple membranes stacked together); SEM analysis of the gas suppression membrane yielded the following results. Figure 3 As shown; SEM characterization shows that the fiber diameter of the gas suppression membrane is approximately 300 nm.

[0079] Example 2 Example 2 is similar to Example 1, except that PVA, CaO nanopowder (primary particle size 120 nm) and Co-TPP (primary particle size 120 nm) were weighed in a mass ratio of 1:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0080] Example 3 Example 3 is similar to Example 1, except that PVA, PAN, CaO nanopowder (primary particle size 120 nm) and CeO2 (primary particle size 120 nm) were weighed in a mass ratio of 0.5:0.5:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0081] Example 4 Example 4 is similar to Example 1, except that PVA, PAN, CaO nanopowder (primary particle size 250 nm) and Co-TPP (primary particle size 120 nm) were weighed in a mass ratio of 0.5:0.5:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0082] Example 5 Example 5 is similar to Example 1, except that PVA, PAN, CaO nanopowder (primary particle size 120 nm) and Co-TPP (primary particle size 300 nm) were weighed in a mass ratio of 0.5:0.5:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0083] Example 6 Example 6 is similar to Example 1, except that PVA, PAN, CaO nanopowder (primary particle size 120 nm) and Co-TPP (primary particle size 120 nm) were weighed in a mass ratio of 0.5:0.5:0.1:0.1 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0084] Example 7 Example 7 is similar to Example 1, except that PVA, PAN, CaO nanopowder (primary particle size 500 nm) and Co-TPP (primary particle size 120 nm) were weighed in a mass ratio of 0.5:0.5:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0085] Example 8 Example 8 is similar to Example 1, except that PVA, PAN, CaO nanopowder (primary particle size 120 nm) and Co-TPP (primary particle size 600 nm) were weighed in a mass ratio of 0.5:0.5:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0086] Example 9 Example 9 is similar to Example 1, except that PAN, CaO nanopowder (primary particle size 120 nm) and Co-TPP (primary particle size 120 nm) were weighed in a mass ratio of 1:0.2:0.2 to prepare a gas suppression film. All other preparation process conditions are the same as in Example 1.

[0087] Comparative Example 1 Comparative Example 1 is similar to Example 1, except that CaO nanopowder was not added. PVA, PAN and Co-TPP (120 nm particle size) were weighed in a mass ratio of 0.5:0.5:0.2. Co-TPP was first added to DMF solvent and sonicated for 5 min. Then PVA and PAN powder were slowly added and stirred until completely dissolved to form a uniform, bubble-free viscous spinning solution. All other preparation process conditions were the same as in Example 1.

[0088] Comparative Example 2 Comparative Example 2 is similar to Example 1, except that Co-TPP was not added. PVA, PAN, and CaO nanoparticles (120 nm particle size) were weighed in a mass ratio of 0.5:0.5:0.2. CaO was first added to DMF solvent and sonicated for 5 min. Then, PVA and PAN powders were slowly added and stirred until completely dissolved to form a uniform, bubble-free viscous spinning solution. All other preparation process conditions were the same as in Example 1.

[0089] Test case The contact angle between the gas suppression membrane and water and the gas purification effect prepared in each embodiment and comparative example were tested respectively. The test methods are as follows: Contact angle test: A drop of pure water (usually 1-5 μL) is dropped onto the material surface using a microsyringe. The image of the water droplet is captured by an optical device (camera). The angle between the droplet profile and the tangent at the contact point with the solid surface is analyzed by software. This angle is the contact angle. Gas purification effect test: The membrane was placed in two sealed containers. A mixture of O2, SO2 and H2S gas was introduced into container one. The mass fraction of O2, SO2 and H2S in container one was 2%, and the remaining gas was argon. Moist air (70% humidity) was introduced into container two. The internal temperature sensor of the membrane was connected to the conversion module and the computer. After 10 minutes, the content of each gas in device one was measured and the heating rate of device two was read. The test results are shown in Table 1.

[0090] Table 1

[0091] As shown in Table 1, the gas suppression membrane prepared by the method of the present invention has a high purification rate for O2, SO2 and H2S. It can effectively remove O2 and SO2 generated during normal battery operation, and absorb the generated H2S in the early stage of failure, delaying the release of H2S to the outside environment. It can also react with H2O in the air and release heat, so that the heating rate of the gas suppression membrane reaches the preset value, thereby triggering an alarm to achieve safety control.

[0092] As can be seen from the results of Example 1 and Comparative Example 1, adding an acid remover to the gas suppression membrane can significantly improve the removal rate of SO2 and H2S, and can significantly improve the heating rate after contact with humid air, so as to realize the alarm.

[0093] As can be seen from the results of Examples 1, 3 and Comparative Example 2, adding an oxygen absorber to the gas suppression membrane can significantly improve the O2 removal rate, and Co-Tpp has a better oxygen absorption effect than CeO2.

[0094] As can be seen from the results of Examples 1, 4 and 7, as the primary particle size of the acid remover increases, the removal rate of SO2 and H2S decreases, and the heating rate also decreases after contact with H2O in humid air.

[0095] As can be seen from the results of Examples 1, 5 and 8, the O2 removal rate decreases as the primary particle size of the oxygen absorber increases.

[0096] As can be seen from the data in Examples 1 and 6, the proportion of acid remover and oxygen absorber decreased, the removal rate of O2, SO2 and H2S decreased, and the heating rate also decreased after contact with humid air.

[0097] As can be seen from the data in Examples 1 and 9, the hydrophilicity of the polymer matrix affects the hydrophilicity of the gas suppression membrane. Good hydrophilicity is more conducive to the enrichment of H2O in the air on the gas suppression membrane, which is beneficial to the contact and reaction of H2O with the deacidifying agent. The hydrophilic gas suppression membrane has a higher heating rate after contacting humid air, and is more suitable for safety control systems.

[0098] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A gas barrier film, characterized by, The gas inhibition film comprises a polymer matrix, and an acid scavenger and an oxygen absorber supported on the polymer matrix; the acid scavenger comprises calcium oxide; the oxygen absorber comprises at least one of CeO2, nitrogen-doped graphene and a metal organic framework material.

2. The gas barrier film according to claim 1, characterized by At least one of the following characteristics is satisfied: (1) the metal organic framework material comprises cobalt tetraphenylporphyrin; (2) the primary particle size of the acid scavenger is 20-500 nm; (3) the primary particle size of the oxygen absorber is 20-600 nm; (4) the polymer comprises at least one of polyvinyl alcohol, polyvinylpyrrolidone and polyacrylonitrile.

3. The gas barrier film according to claim 1, wherein The mass ratio of the polymer, the acid scavenger and the oxygen absorber is 1:0.02-0.3:0.02-0.

3.

4. The gas barrier film according to claim 1, wherein At least one of the following characteristics is satisfied: (1) the fiber diameter of the gas inhibition film is 100-500 nm; (2) the thickness of the gas inhibition film is 5-50 μm.

5. The gas barrier film according to claim 1, wherein The contact angle of the gas inhibition film with water is 5-30°.

6. The method of producing a gas barrier film according to any one of claims 1 to 5, characterized by, The method comprises the following steps: mixing an acid scavenger, an oxygen absorber and a polymer with a solvent to obtain a spinning solution; and using an electrostatic spinning method to form a film, and vacuum drying to obtain the gas inhibition film.

7. The method for producing a gas barrier film according to claim 6, wherein At least one of the following characteristics is satisfied: (1) the solvent comprises DMF and / or THF; (2) the mass ratio of the solvent to the polymer is 7-13:1; (3) the push injection rate of the electrostatic spinning is 0.1-3.0 mL / h, the voltage is 10-30 kV, and the receiving distance is 10-25 cm; (4) the time of the electrostatic spinning is 1-10 h; (5) the temperature of the vacuum drying is 60-100℃, and the time is 1-3 h.

8. A sulfide solid-state battery characterized by comprising: The gas inhibition film according to any one of claims 1-5.

9. A sulfide solid-state battery safety prevention and control system, characterized by, The gas inhibition film according to any one of claims 1-5; The gas inhibition film is arranged inside a sulfide solid-state battery monomer cell, a temperature sensor is arranged on the gas inhibition film, the temperature sensor is connected with a battery management system, the battery management system is connected with an alarm, and when a detected temperature rise rate reaches a preset temperature rise rate, the alarm alarms.

10. The sulfide solid-state battery safety prevention system according to claim 9, wherein At least one of the following characteristics is satisfied: (1) the arrangement mode of the gas inhibition film inside the monomer cell is to be wound outside a pole group or a roll core inside the monomer cell; (2) the preset temperature rise rate is 0.5-10℃ / min.

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