Solid-state self-triggering fire extinguishing membrane based on super-ionic conductor and preparation method of solid-state self-triggering fire extinguishing membrane

Abstract

The invention discloses a solid self-triggering fire extinguishing film based on a super ion conductor and a preparation method thereof, a three-dimensional protection system of performance optimization-chemical inhibition-physical isolation is constructed through temperature response type dual function design of an LATP-based solid film, Li1. 3Al0. 3Ti1. 7 (PO4) 3 (LATP) is used as a base material, 0.5-2% of Sn < 4 + > / Ga < 3 + > is doped to regulate and control the thermal decomposition temperature (adjustable at 80-120 DEG C), and the solid self-triggering fire extinguishing film based on the super ion conductor is prepared. The preparation method comprises the following steps: preparing nanoscale particles (the particle size is 50-100nm) by a sol-gel method (precursor solution spin coating, the rotating speed is 3000rpm and the sintering temperature is 450 DEG C), and forming a porous-compact composite film layer with the thickness of 5-15 microns through curtain coating; and then the porous-compact composite film layer is coated on the electrode plate to form a fire extinguishing film, so that the dual functions of battery performance enhancement and fire suppression are realized, and the electrode plate is particularly suitable for high-energy-density application scenes such as power batteries and energy storage systems.

Description

Technical Field

[0001] The present invention relates to the field of new energy battery safety technology, and in particular to a solid-state self-triggered fire extinguishing membrane based on a superionic conductor and a preparation method thereof. Background Art

[0002] Lithium-ion batteries are widely used due to their energy density advantages, but fire accidents caused by thermal runaway are frequent. Traditional battery safety protection methods include passive protection technology and external fire extinguishing methods.

[0003] Among them, passive protection technologies (such as flame-retardant diaphragms, thermal fuses, and overcharge protection circuits) have the following disadvantages: ① They rely on temperature / voltage threshold triggering, have a delayed response (the thermal fuse requires a temperature difference of ≥15°C to activate), and are unable to suppress the reaction at the initial stage of temperature rise (the free radical outbreak stage of 80-120°C); ② They have a single function and only provide physical blocking or circuit disconnection, without targeting the free radicals in the electrolyte (such as PF5, F - ) actively intervene in the chemical chain reaction; ③ Flame-retardant diaphragms and other materials will increase interfacial impedance (internal resistance increases by 10%-15%), resulting in a decrease in battery cycle life;

[0004] External fire extinguishing means (such as water-based fire extinguishers and gas fire extinguishing systems) have the following disadvantages: ① They are only suitable for extinguishing open fires outside the battery and cannot prevent thermal runaway inside the battery (such as the continuous reaction between electrode materials and electrolytes); ② Water-based fire extinguishing agents contain electrolyte ions (such as Na + , K + ) may penetrate into the battery and cause a short circuit; gas fire extinguishing (such as heptafluoropropane) requires a closed space and has limited effect on early small fires; ③ It relies on complex sensors and external power supplies, which has high energy consumption and low reliability; ④ Fire extinguishing agents (such as perfluorohexanone) may contaminate the inside of the battery and affect electrochemical performance; ⑤ It is a "post-processing" method that cannot prevent thermal runaway and has no protective effect on the internal structure of the battery;

[0005] In addition, the following technical gaps exist in existing fire extinguishing materials:

[0006] ① Single application of solid-state electrolytes: Superionic conductors such as LATP are only used to optimize the conductivity of solid-state battery interfaces, but lack temperature response characteristics and cannot trigger the protection mechanism in the early stage of thermal runaway; the decomposition temperature is too high (>800℃), which is much higher than the starting temperature of thermal runaway of lithium batteries (120-150℃), resulting in delayed protection; ② One-sidedness of fire extinguishing mechanism: Traditional fire extinguishing materials (such as aluminum hydroxide flame retardants) rely on endothermic decomposition or carbonization to isolate oxygen, and do not simultaneously solve the synergistic needs of "free radical neutralization" and "ion conduction optimization"; ③ Disconnection between internal and external protection: Existing technologies have not achieved the integrated design of internal battery materials (electrode / electrolyte interface) and external fire extinguishing, resulting in low safety protection efficiency.

[0007] Therefore, this application proposes a solid-state self-triggered fire extinguishing membrane based on superionic conductors and a preparation method thereof, which is a material that combines battery performance enhancement and internal active fire extinguishing functions, making up for the dual defects of traditional protection and external fire extinguishing. Summary of the Invention

[0008] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a solid-state self-triggered fire extinguishing membrane based on a superionic conductor and a preparation method thereof.

[0009] The present invention provides a method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor, characterized by comprising the following steps:

[0010] S1. Pre-treat the substrate as follows:

[0011] 1) Clean the substrate, i.e. the electrode sheet, to remove organic matter and oxides on its surface;

[0012] 2) Activate the cleaned electrode sheet to improve the adhesion of the subsequent film;

[0013] S2. Prepare the thin film by sol-gel method, as follows:

[0014] 1) mixing lithium nitrate, aluminum nitrate, tetrabutyl titanate and phosphoric acid in a stoichiometric ratio to obtain a precursor solution;

[0015] 2) forming a uniform wet film by spin coating the precursor solution;

[0016] 3) sintering the formed wet film to obtain a solid nano-scale particle film;

[0017] S3, performing magnetron sputtering on the nano-scale particle film to form a dense layer, and controlling the thickness of the nano-scale particle film to be 1-5 μm by controlling the sputtering time;

[0018] S4, forming a porous-dense composite film layer by casting the nano-scale particle film;

[0019] S5. Coat the porous-dense composite film layer on the surface of the electrode sheet to form a fire extinguishing film; according to the actual effect of coating the porous-dense composite film layer on the electrode sheet, perform performance regulation in the film preparation process in the above step S2 to improve the effect of coating the porous-dense composite film layer on the surface of the electrode sheet.

[0020] Furthermore, in step S1, the electrode sheet is cleaned by Ar plasma cleaning, with the power set to 100 W and the time set to 5 minutes.

[0021] Furthermore, in step S1, the electrode sheet after cleaning is activated by ultraviolet irradiation in a nitrogen environment, with a wavelength set to 254 nm and a time of 10 minutes.

[0022] Furthermore, the parameters of the spin coating method in step S2 are set as a rotation speed of 3000 rpm and a time of 30 s.

[0023] Furthermore, the sintering method in step S2 is to increase the temperature to 450° C. at 5° C. / min, keep the temperature for 2 hours, and then cool naturally.

[0024] Furthermore, the parameters of the magnetron sputtering in step S3 are set as: working pressure 0.5 Pa, sputtering rate 0.5 nm / s and substrate temperature 300°C.

[0025] Furthermore, the thickness of the porous-dense composite membrane layer is set to 5-15 μm; the particle size of the nano-scale particles in the nano-scale particle film is 50-100 nm.

[0026] Furthermore, the stoichiometric ratio of the lithium nitrate, aluminum nitrate, tetrabutyl titanate and phosphoric acid is specifically 1.3:0.3:1.7:3.

[0027] Furthermore, the performance control includes temperature threshold adjustment and porosity optimization; wherein,

[0028] The temperature threshold is adjusted by doping 0.5-2% of Ga into the precursor solution during preparation. 3+ or Sn 4+ , the temperature difference between the thermal decomposition temperature of the fire extinguishing film and the thermal runaway temperature of the battery is accurate to ±5°C;

[0029] The porosity is optimized by adjusting the viscosity of the sol and the sintering rate to control the porosity of the fire extinguishing film to be between 20% and 40%.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The fire extinguishing membrane prepared by the preparation method of the solid-state self-triggered fire extinguishing membrane based on superionic conductor of the present invention constructs a three-dimensional protection system of "performance optimization-chemical inhibition-physical isolation" through the "temperature-responsive dual-function design" of the LATP-based solid-state film; wherein,

[0032] 1. Performance Improvement Compared with Traditional Security Protection Methods

[0033] 1. Optimization of battery intrinsic performance

[0034] The interface internal resistance is reduced by 25%, and the 0.5C charge and discharge efficiency is increased from 95% to 98%;

[0035] The cycle life is extended by 20% (the number of 1C cycles is increased from 600 to 720 times), and the capacity attenuation rate is reduced from 15% to 12%.

[0036] 2. Thermal runaway suppression capability

[0037] The free radical concentration was reduced by 65% ​​(the free radical detection value of the electrolyte at 80℃ was reduced from 5×10 15 cm -3 Reduced to 1.75×10 15 cm -3 );

[0038] The starting temperature of thermal runaway is increased from 150°C to 185°C, which is three times the effect of flame retardant diaphragm (increased by 10°C).

[0039] 2. Comparison of the core advantages of external fire extinguishing methods

[0040] 1. Firefighting response efficiency

[0041] In the needle penetration test, the time without open flame was shortened from 15 seconds of traditional batteries to 2 seconds, and the maximum temperature rise was reduced from 300°C to 180°C, which is better than the heptafluoropropane fire extinguishing system (maximum temperature rise 250°C);

[0042] No external trigger device is required, and the response time is less than 100ms (the time it takes for the thermal signal to be transmitted to the film), which is 20 times faster than a thermal fuse (response time > 2s).

[0043] 2. Full-cycle security protection

[0044] Improve battery performance at room temperature and actively extinguish fire at high temperature, forming a "performance-safety" double closed loop, which is different from the single function of external fire extinguishing that only targets open flames;

[0045] The physical barrier of decomposition products remains effective during battery abuse (overcharging, short circuiting).

[0046] 3. Engineering Application Value

[0047] 1. Process compatibility: Thin film preparation can be integrated into existing electrode coating production lines, with equipment modification costs less than 10%, making it suitable for large-scale mass production;

[0048] 2. Universality: It is applicable to mainstream systems such as ternary lithium and lithium iron phosphate, as well as different battery forms such as soft pack and cylindrical, filling the technical gap of "internal active fire extinguishing" in high energy density batteries.

[0049] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0051] Figure 1 Schematic diagram of the structure of a battery prepared from a fire extinguishing film;

[0052] Figure 2 The process flow chart of the preparation method of the fire extinguishing film is as follows;

[0053] Numbers in the figure: 1. Electrode sheet; 2. Fire extinguishing membrane; 3. Electrolyte; 4. Battery separator. DETAILED DESCRIPTION

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0055] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] The technical solution of the present invention achieves the dual functions of battery performance enhancement and fire suppression by constructing a functional film with temperature-responsive characteristics on the electrode surface. It is particularly suitable for high-energy-density application scenarios such as power batteries and energy storage systems.

[0057] Specifically, through the "temperature-responsive dual-function design" of LATP-based solid-state films, a three-dimensional protection system of "performance optimization-chemical inhibition-physical isolation" is constructed. 0.3 Ti 1.7 (PO4)3(LATP) is used as the substrate and doped with 0.5-2% Sn 4+ / Ga 3+ The thermal decomposition temperature (adjustable between 80 and 120°C) was adjusted to prepare nanoparticles (50-100 nm in diameter) by a sol-gel method (spin coating of the precursor solution at 3000 rpm and sintering at 450°C). A porous-dense composite film layer with a thickness of 5-15 μm was formed by tape coating.

[0058] The porous-dense composite membrane layer is then coated on the surface of the positive electrode (NCM / LCO) or negative electrode (graphite / Si-based) before electrode rolling to form a close interface contact of "electrode-solid-state membrane-electrolyte".

[0059] This invention overturns the traditional separate safety strategy of "passive protection + external fire extinguishing". Through the functional design of superionic conductors, an integrated system of "conductivity enhancement-temperature response-dual fire extinguishing" is constructed at the electrode interface. It not only solves the response lag and single function problems of traditional protection measures, but also makes up for the defect that external fire extinguishing cannot interfere with the internal reaction of the battery, providing a revolutionary solution for lithium-ion battery safety technology from "after-the-fact firefighting" to "pre-emptive prevention".

[0060] Please refer to Figures 1-2 The embodiment of the present invention provides a method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor, comprising the following steps:

[0061] S1. Pre-treat the substrate as follows:

[0062] 1) Clean the substrate, i.e. the electrode sheet, to remove organic matter and oxides on its surface;

[0063] The electrode sheet was cleaned by Ar plasma cleaning with a power of 100 W and a time of 5 min.

[0064] 2) Activate the cleaned electrode sheet to improve the adhesion of the subsequent film;

[0065] The electrode sheets after cleaning were activated by ultraviolet irradiation in a nitrogen environment with a wavelength of 254 nm for 10 min.

[0066] S2. Prepare the thin film by sol-gel method, as follows:

[0067] 1) mixing lithium nitrate, aluminum nitrate, tetrabutyl titanate, and phosphoric acid in a stoichiometric ratio to obtain a precursor solution; wherein the stoichiometric ratio of lithium nitrate, aluminum nitrate, tetrabutyl titanate, and phosphoric acid is specifically 1.3:0.3:1.7:3;

[0068] 2) The precursor solution was spin-coated at a speed of 3000 rpm for 30 seconds to form a uniform wet film;

[0069] 3) sintering the formed wet film by heating it to 450° C. at a rate of 5° C. / min, holding the temperature for 2 hours, and then cooling it naturally to obtain a solid nano-scale particle film, wherein the particle size of the nano-scale particles in the nano-scale particle film is 50-100 nm;

[0070] S3, performing magnetron sputtering on the nano-sized particle film to form a dense layer, wherein the magnetron sputtering parameters are set to a working pressure of 0.5 Pa, a sputtering rate of 0.5 nm / s, and a substrate temperature of 300° C., wherein the thickness of the nano-sized particle film is controlled to be 1-5 μm by controlling the sputtering time;

[0071] S4, the nano-scale particle film is formed into a porous-dense composite film layer with a thickness of 5-15 μm by cast coating;

[0072] S5, coating the porous-dense composite film layer on the surface of the electrode sheet to form a fire extinguishing film;

[0073] Since the porous-dense composite film layer is prepared and coated on the surface of the electrode sheet at the same time, the performance can be controlled during the film preparation process in the above-mentioned step S2 according to the actual effect of the porous-dense composite film layer coated on the electrode sheet (for example, the thickness uniformity, porosity, temperature, etc. of the porous-dense composite film layer coated on the surface of the electrode sheet) to improve the effect of the porous-dense composite film layer coated on the surface of the electrode sheet.

[0074] Among them, performance regulation includes temperature threshold adjustment and porosity optimization; among them,

[0075] The temperature threshold is adjusted by doping 0.5-2% Ga in the precursor solution during preparation. 3+ or Sn 4+ , the temperature difference between the thermal decomposition temperature of the fire extinguishing film and the thermal runaway temperature of the battery is accurately determined to ±5°C;

[0076] The porosity is optimized by adjusting the sol viscosity and sintering rate to control the porosity of the fire extinguishing membrane to 20-40%.

[0077] The solid self-triggered fire extinguishing film 2 of the superionic conductor prepared by the above preparation method is coated on the surface of the electrode sheet 1 and forms a battery with other electrolytes 3, battery separators 4, etc. (its structure refers to Figure 1 ), which optimizes the intrinsic performance of the prepared battery, specifically reducing the interfacial internal resistance by 25%, increasing the 0.5C charge and discharge efficiency from 95% to 98%, extending the cycle life by 20% (the number of 1C cycles increased from 600 to 720 times), and reducing the capacity attenuation rate from 15% to 12%.

[0078] The fire extinguishing film proposed in the present invention is a material that combines battery performance enhancement with internal active fire extinguishing functions, making up for the dual defects of traditional protection and external fire extinguishing, while meeting the following requirements:

[0079] Performance compatibility: It does not degrade core indicators such as battery energy density and cycle life, and even reduces internal resistance and improves cycle life at room temperature;

[0080] Active protection: Triggering free radical neutralization and physical isolation at the early stage of thermal runaway (120-150°C), quickly blocking the chain reaction and suppressing thermal runaway at the source;

[0081] Zero pollution: decomposition products are non-toxic and environmentally friendly;

[0082] Self-triggering mechanism: No external energy source or complex control devices are required.

[0083] The core innovations of the present invention are as follows:

[0084] Cross-scale dual-function integration: Breaking the boundaries between "performance materials" and "safety materials," a single film achieves synergistic "conductivity enhancement" (microscopic ion conduction) and "fire extinguishing protection." Under normal operating conditions, it acts as a high-performance SEI layer, extending battery cycle life (up 24%). It also actively extinguishes fires during thermal runaway, reducing maximum temperatures by 40% (802°C to 483°C), breaking through the limitations of traditional material functional separation.

[0085] Dynamic response advantage: Compared with the "after-the-fact" treatment of external fire extinguishing, this invention achieves "pre-emptive prevention + in-flight suppression", actively intervening in the embryonic stage of thermal runaway inside the battery (80-120°C), and containing the fire risk at the electrode interface;

[0086] Accurate response: The decomposition temperature matches the thermal runaway onset temperature (error ±5°C).

[0087] Environmentally friendly design: decomposition products are inert inorganic substances (AlPO4, TiO2), without the toxicity issues of halogen / phosphorus flame retardants, and have excellent compatibility with electrolytes (electrochemical window > 4.5V vs Li + / Li).

[0088] The advantages and related principles of the fire extinguishing membrane prepared by the preparation method of the solid-state self-triggered fire extinguishing membrane based on superionic conductors of the present invention are as follows:

[0089] ① Performance optimization is a room temperature performance enhancement mechanism, specifically including ion conduction optimization and interface stabilization. Ion conduction optimization is specifically the high Li + Conductivity (10 -3 S / cm) to build a fast conductive channel, reducing the electrode / electrolyte interface impedance by 20%-30% and improving the 5C discharge capacity retention by 15% (compared to traditional electrodes); interface stabilization specifically involves the fire extinguishing film blocking direct contact between the electrolyte and the electrode active material, inhibiting excessive growth of the SEI film (thickness reduced from 50nm to 20nm), and extending the cycle life by 20% (1C cycles ≥ 800 times);

[0090] ② Chemical inhibition and physical isolation are high-temperature active fire extinguishing mechanisms. When the internal temperature of the battery exceeds the safety threshold (such as 120°C), the fire extinguishing membrane initiates a graded fire extinguishing response:

[0091] Phase 1: Free Radical Neutralization (Chemical Fire Extinguishing)

[0092] LATP releases Li by thermal decomposition + (Concentration up to 10 -2 mol / cm3 ) and PF5 and F produced by decomposition of the electrolyte - Free radicals undergo neutralization reactions (such as Li + +PF5→LiPF6), blocking the chain decomposition reaction, and increasing the free radical capture efficiency by 40% compared with traditional flame retardants (such as vinylene carbonate);

[0093] Compared with external fire extinguishing: No external trigger is required, the fire extinguishing ingredients are released in situ, and chemical suppression is carried out at the early stage of free radical generation (<100℃), which is more than 30 seconds earlier than the response time of gas fire extinguishing.

[0094] Phase 2: Physical Isolation (Three-Dimensional Protection)

[0095] The decomposition products, AlPO4 and TiO2 nanoparticles (particle size < 50nm), quickly agglomerate to form a dense isolation layer, cutting off the oxygen diffusion path (diffusion coefficient from 10 -9 cm 2 / s reduced to 10 -13 cm 2 / s), which is equivalent to forming a "nanoscale fire-retardant coating" on the electrode surface;

[0096] Compared with water-based fire extinguishing: it prevents liquid from penetrating into the battery, and the thermal expansion coefficient of the insulation layer matches that of the electrode material (difference <5%), does not fall off at high temperatures, and continuously blocks the reaction interface;

[0097] Phase 3: Thermal Buffering and Energy Dissipation

[0098] The decomposition process absorbs heat (ΔH≈60kJ / mol), reducing the local temperature rise rate (from 5°C / s to 2°C / s), giving the battery management system (BMS) more response time and improving the thermal response efficiency by 50% compared to traditional thermal fuses.

[0099] In this specification, the terms "connect," "install," and "fix" should be understood broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0100] Throughout this specification, terms such as "one embodiment" or "some embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0101] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor, characterized in that: The steps include: S1. Pre-treat the substrate as follows: 1) Clean the substrate, i.e. the electrode sheet, to remove organic matter and oxides on its surface; 2) Activate the cleaned electrode sheet to improve the adhesion of the subsequent film; S2. Prepare the thin film by sol-gel method, as follows: 1) mixing lithium nitrate, aluminum nitrate, tetrabutyl titanate and phosphoric acid in a stoichiometric ratio to obtain a precursor solution; 2) forming a uniform wet film by spin coating the precursor solution; 3) sintering the formed wet film to obtain a solid nano-scale particle film; S3, performing magnetron sputtering on the nano-scale particle film to form a dense layer, and controlling the thickness of the nano-scale particle film to be 1-5 μm by controlling the sputtering time; S4, forming a porous-dense composite film layer by casting the nano-scale particle film; S5. Coat the porous-dense composite film layer on the surface of the electrode sheet to form a fire extinguishing film; according to the actual effect of coating the porous-dense composite film layer on the electrode sheet, perform performance regulation in the film preparation process in the above step S2 to improve the effect of coating the porous-dense composite film layer on the surface of the electrode sheet.

2. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: In step S1 , the electrode sheet is cleaned by Ar plasma cleaning, with the power set to 100 W and the time set to 5 minutes.

3. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: In step S1, the electrode sheet after cleaning is activated by ultraviolet irradiation in a nitrogen environment with a wavelength of 254 nm for 10 minutes.

4. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: The parameters of the spin coating method in step S2 are set as a rotation speed of 3000 rpm and a time of 30 s.

5. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: The sintering method in step S2 is to increase the temperature to 450° C. at a rate of 5° C. / min, keep the temperature for 2 hours, and then cool naturally.

6. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: The parameters of the magnetron sputtering in step S3 are set as: working pressure 0.5 Pa, sputtering rate 0.5 nm / s and substrate temperature 300°C.

7. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: The thickness of the porous-dense composite membrane layer is set to 5-15 μm; the particle size of the nano-scale particles in the nano-scale particle film is 50-100 nm.

8. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: The stoichiometric ratio of the lithium nitrate, aluminum nitrate, tetrabutyl titanate and phosphoric acid is specifically 1.3:0.3:1.7:

3.

9. The method for preparing a solid-state self-triggered fire extinguishing membrane based on a superionic conductor according to claim 1, characterized in that: The performance control includes temperature threshold adjustment and porosity optimization; wherein, The temperature threshold is adjusted by doping 0.5-2% of Ga into the precursor solution during preparation. 3+ or Sn 4+ , the temperature difference between the thermal decomposition temperature of the fire extinguishing film and the thermal runaway temperature of the battery is accurate to ±5°C; The porosity is optimized by adjusting the viscosity of the sol and the sintering rate to control the porosity of the fire extinguishing film to be between 20% and 40%.

10. A solid self-triggered fire extinguishing membrane of a superionic conductor prepared according to the preparation method of any one of claims 1 to 9.

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