Solid electrolyte diaphragm as well as preparation method and application thereof

Abstract

The invention discloses a solid electrolyte diaphragm and a preparation method and application thereof, the solid electrolyte diaphragm comprises a porous diaphragm, the porous diaphragm comprises a bacterial cellulose composite membrane, and the bacterial cellulose composite membrane comprises a bacterial cellulose membrane and a metal organic framework loaded in the bacterial cellulose membrane; and the butanedinitrile is permeated into the bacterial cellulose composite membrane. According to the porous diaphragm provided by the invention, the bacterial cellulose is used as a diaphragm framework, the materials are easy to obtain, the price is low, the production cost is low, SN molecules are accurately anchored through the MOF pore channel confinement effect, and a through type three-dimensional ion transmission network is constructed, so that the ion transmission efficiency is improved. The preparation method of the solid electrolyte membrane provided by the invention is simple in steps, easy to operate and practical, and adopts a liquid phase layer-by-layer self-assembly technology, and the MOF loading procedure is completed at normal temperature and normal pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage materials, and in particular to a solid electrolyte diaphragm and a preparation method and application thereof. Background Art

[0002] Solid-state lithium metal batteries (LMBs) are considered a core development direction for next-generation, high-safety energy storage systems due to their theoretical mass energy density exceeding 500Wh / kg, inherent thermal stability temperatures exceeding 300°C, and ability to suppress lithium dendrites. However, their large-scale commercialization still faces bottlenecks in key material properties, particularly the ion transport efficiency of solid electrolyte separators. While current mainstream polymer-based solid electrolytes (such as PEO systems) possess excellent interfacial wettability and flexible processing properties, their ion conduction mechanisms rely on the local relaxation motion of polymer chains and the hopping transport of coordination sites, resulting in generally low room-temperature ionic conductivity, which is not conducive to efficient lithium ion transport and the proper performance of electrochemical performance. As a plastic crystal, succinonitrile (SN) has a high polarity terminal cyano group, which results in high solubility for lithium salts. The end group also provides an excellent electrochemical window. The room-temperature ionic conductivity of SN-lithium salt composite systems can be improved by two orders of magnitude compared to traditional PEO-based electrolytes. However, SN needs to be present at a higher content to form an ion transport network in the polymer electrolyte, which leads to a significant deterioration in the mechanical strength of the polymer electrolyte. Summary of the Invention

[0003] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, the present invention aims to provide a solid electrolyte membrane and a preparation method and application thereof.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A first aspect of the present invention provides a porous membrane comprising:

[0006] A bacterial cellulose composite membrane, comprising a bacterial cellulose membrane and a metal organic framework loaded in the bacterial cellulose membrane;

[0007] Succinonitrile, wherein the succinonitrile permeates the bacterial cellulose composite membrane.

[0008] In the present invention, the bacterial cellulose membrane has a three-dimensional nano-network structure, and the high specific surface area and uniform pore size distribution characteristics unique to the metal organic framework (MOF) can form a topological adaptation with the three-dimensional nano-network structure in the bacterial cellulose membrane, and form a three-dimensional interpenetrating ion transport network with the bacterial cellulose membrane. Succinonitrile permeates the bacterial cellulose composite membrane, and the MOF pore confinement effect can anchor succinonitrile to form a through-type nanochannel, which can provide multiple ion transport paths, thereby significantly reducing the migration resistance of ions and improving the ionic conductivity and ion migration number.

[0009] In some embodiments of the present invention, the metal organic framework in the bacterial cellulose composite membrane anchors the succinonitrile.

[0010] In some embodiments of the present invention, the bacterial cellulose membrane has a three-dimensional nanofiber network structure.

[0011] In some embodiments of the present invention, the metal-organic framework has a three-dimensional network structure.

[0012] In some embodiments of the present invention, the bacterial cellulose membrane is modified with an aminosilane surface coupling agent and then loaded with a metal-organic framework. In this invention, the aminosilane surface coupling agent modified on the bacterial cellulose membrane provides surface active sites. The amino functional groups can serve as anchoring sites for metal ions in the MOF material, facilitating the uniform loading of the MOF on the three-dimensional nanostructure of the bacterial cellulose membrane.

[0013] In some embodiments of the present invention, the mass ratio of the bacterial cellulose membrane to the metal organic framework is 1.5-3:0.5-1, such as 1.5-1.8:0.5-1.

[0014] In some embodiments of the present invention, the mass ratio of the bacterial cellulose membrane to succinonitrile is 0.4-2.5:0-1.1, such as 0.4-2.5:0.1-1.06, or 1.5-1.8:0.1-1.06.

[0015] In some embodiments of the present invention, the mass ratio of the bacterial cellulose membrane to the aminosilane surface coupling agent is 0.4-3.5:0.1-0.5, such as 0.4-3.2:0.1-0.5, or 1.5-1.8:0.1-0.32.

[0016] In some embodiments of the present invention, the thickness of the bacterial cellulose membrane is 15 μm to 45 μm.

[0017] In some embodiments of the present invention, the metal organic framework includes at least one of Al-MOF (MIL-53), Zr-MOF (UIO-66), Zn-MOF (ZIF-8), Co-MOF (ZIF-67), Ce-MOF (MOF-808), Ti-MOF (MIL-125) or Cu-MOF (HKUST-1).

[0018] In some embodiments of the present invention, the aminosilane surface coupling agent includes at least one of KH-550, KH-540, KH-792, KH-602, KH-902, KH-A115, KH-A117, KH-A118, and KH-903.

[0019] A second aspect of the present invention provides a solid electrolyte membrane, comprising the porous membrane and a solid electrolyte precursor.

[0020] In some embodiments of the present invention, the porous membrane comprises succinonitrile and a precursor of the solid electrolyte, which are polymerized in situ on the bacterial cellulose composite membrane. In this invention, the porous membrane provides multiple ion transport pathways, significantly reducing the migration resistance of lithium ions in the electrolyte and improving the ionic conductivity and lithium ion transference number of the solid electrolyte, resulting in excellent electrochemical performance and good cycling stability.

[0021] In some embodiments of the present invention, the precursor of the solid electrolyte includes the following preparation raw materials: a polymer monomer, a lithium salt, and a functional additive.

[0022] In some embodiments of the present invention, the volume ratio of the polymerization monomer to the functional additive is 25 to 35:1.

[0023] In some embodiments of the present invention, the polymerizable monomer includes a cyclic ether compound, such as at least one of propylene oxide, 2,3-butylene oxide, 1,3-dioxolane (DOL), 1,4-dioxane, 1,4-butylene oxide (THF) and perfluorocyclic ether.

[0024] In some embodiments of the present invention, the lithium salt includes at least one of lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide (LiFTSI), lithium bis(fluorosulfonyl)imide, lithium difluorooxalatoborate (LiDFOB), lithium nitrate, lithium perchlorate, or lithium tetrafluoroborate.

[0025] In some embodiments of the present invention, in the lithium salt, the molar ratio of lithium bis(trifluoromethanesulfonyl)imide to lithium difluorooxalatoborate is 1:(0.02-1); such as 1:(0.05-0.1), 1:(0.2-0.8), 1:0.9 or 1:1.

[0026] In some embodiments of the present invention, the molar concentration of the lithium salt in the solid electrolyte precursor is 0.2 to 2 mol / L.

[0027] In some embodiments of the present invention, the functional auxiliary agent includes at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylene carbonate (EC), vinylene carbonate (VC), methylene ethylene carbonate (VEC), fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC) or trifluoropropylene carbonate (TFEC).

[0028] The third aspect of the present invention provides a method for preparing the solid electrolyte membrane, comprising the following steps:

[0029] The solid electrolyte membrane is prepared by carrying out an in-situ polymerization reaction between succinonitrile and a precursor of a solid electrolyte on a bacterial cellulose composite membrane.

[0030] In some embodiments of the present invention, the temperature of the in-situ polymerization reaction is 45-60° C.; the time of the in-situ polymerization reaction is 6-20 h, such as 10-15 h, 12 h.

[0031] In some embodiments of the present invention, the method for preparing the bacterial cellulose composite membrane comprises the following steps: immersing the bacterial cellulose membrane in an aminosilane surface coupling agent, and then immersing it in a metal ion solution and an organic ligand solution for self-assembly to obtain the bacterial cellulose composite membrane.

[0032] In some embodiments of the present invention, the metal ion solution and organic ligand solution for forming the MOF material are conventional in the art. Exemplary metal ion solutions include Al 3+ 、Zr 4+ 、Ce 4+ 、Zn 2+ 、Co 2+ 、Ti 2+ 、Cu 2+ exemplary organic ligand solutions include solutions of 2-methylimidazole, terephthalic acid, and trimesic acid.

[0033] A fourth aspect of the present invention provides a solid-state battery comprising the solid-state electrolyte membrane.

[0034] In some embodiments of the present invention, the solid-state battery further includes a positive electrode and a negative electrode; the solid electrolyte membrane is disposed between the positive electrode and the negative electrode.

[0035] In some embodiments of the present invention, when the solid-state battery is a lithium-ion battery, the negative electrode includes a lithium metal negative electrode; the positive electrode includes lithium iron phosphate, lithium nickel cobalt manganese oxide (NCM), or lithium cobalt oxide (LCO).

[0036] The beneficial effects of the present invention are:

[0037] 1) The porous membrane provided by the present invention uses bacterial cellulose as the membrane skeleton. The material is easily available, inexpensive, and has low production cost. The SN molecules are precisely anchored through the MOF pore confinement effect to construct a penetrating three-dimensional ion transport network, thereby improving the ion transport efficiency.

[0038] 2) In some embodiments of the present invention, surface active sites are constructed by pretreatment with a silane coupling agent, which is beneficial to the uniform loading of the metal organic framework material and can further improve the performance of the porous membrane.

[0039] 2) The method for preparing the solid electrolyte membrane provided by the present invention has simple steps, is easy to operate, and is suitable for practical use. It adopts liquid phase layer-by-layer self-assembly technology, and the MOF loading process is completed at room temperature and pressure.

[0040] 3) The solid electrolyte membrane provided by the present invention, as a solid electrolyte membrane for lithium-ion batteries, has high ionic conductivity, high lithium ion migration, excellent electrochemical performance and good cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the SEM image of bacterial cellulose in Comparative Example 1 of the present invention.

[0042] Figure 2 This is an SEM image of the bacterial cellulose membrane loaded with Ce-MOF-808 before silanization in Example 4 of the present invention.

[0043] Figure 3 This is an SEM image of the Ce-MOF-808 bacterial cellulose membrane loaded after silanization in Example 1 of the present invention.

[0044] Figure 4 1 is the XRD pattern of the bacterial cellulose membrane in Example 1 of the present invention and Comparative Example 1.

[0045] Figure 5 These are impedance spectra of the solid electrolyte membranes in Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 of the present invention at room temperature.

[0046] Figure 6 1 and 2 are curves showing the relationship between the ionic conductivity and the different contents of succinonitrile in the solid electrolyte membrane in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention.

[0047] Figure 7 Graph showing the cycling performance test results of the solid electrolyte membrane simulated batteries in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention at a 1C rate.

[0048] Figure 81 and 2 are rate diagrams of the solid electrolyte membrane simulated battery charge and discharge processes in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below using specific examples. Unless otherwise specified, the raw materials, reagents, and apparatus used in the examples and comparative examples are available from conventional commercial sources or by conventional methods. Unless otherwise specified, all experimental or testing methods are conventional in the art.

[0050] 1) The bacterial cellulose used in the following examples and comparative examples is commercially available bacterial cellulose.

[0051] 2) The KH-550 solution used in the following examples and comparative examples was prepared by mixing 3.2 g of 3-aminopropyltriethoxysilane with 157.8 g of anhydrous ethanol, and then adding 17.52 g of water under magnetic stirring to prepare a silane coupling agent solution with a mass fraction of 1.8%.

[0052] 3) The preparation method of the ligand solution of the metal solution used in the following examples is:

[0053] ①Ce 4+ Solution: Dissolve 1.4g Ce(NH4)2(NO3)6·6H2O in 50mL water, stir for 0.5h, then add 22.4mL formic acid to prepare 0.0295mol / L Ce. 3+ solution;

[0054] ②BTC (Benzene-1,3,5-tricarboxylic acid) solution: Dissolve 0.36g of BTC in 50mL of water to prepare a 0.0343mol / L BTC solution.

[0055] ③Zn 2+ Solution: Dissolve 0.45 g zinc acetylacetonate (Zn(acac)2) in 50 mL methanol and stir for 0.5 h;

[0056] ④Co 2+ Solution: Dissolve 0.905 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O) in 50 mL of methanol and stir for 0.5 h;

[0057] ⑤2-MI solution: Dissolve 1.05 g of 2-methylimidazole (2-MI) in 50 mL of methanol and stir for 0.5 h;

[0058] Example 1

[0059] This embodiment prepares a solid electrolyte membrane, and the specific process is as follows:

[0060] 1) Immerse 3.2 g of bacterial cellulose (BC) membrane in deionized water, heat to 90°C, and maintain constant temperature for 2 hours. Immerse the treated BC membrane in 200 mL of 0.5 mol / L sodium hydroxide (NaOH) solution, place it in an oil bath, heat to 110°C, and boil it at constant temperature for about 15 minutes. Immerse it in 200 mL of 1 wt% NaOH solution for 48 hours, then wash it with deionized water until it is neutral. Finally, immerse it in isopropyl alcohol to replace the water in the bacterial cellulose to obtain a purified bacterial cellulose membrane.

[0061] 2) immersing the material obtained in 1) in an ethanol solution of KH-550, and oscillating the solution in a shaker at a low speed for 4 hours to obtain a modified bacterial cellulose gel membrane;

[0062] 3) The modified bacterial cellulose gel membrane obtained in 2) is immersed in Ce 4+ The sample was placed in a formic acid solution and shaken at low speed on a shaker for 8 h. After removal, it was rinsed with deionized water three times and placed in a BTC aqueous solution and stirred at 100 rpm for 24 h.

[0063] 4) The bacterial cellulose composite gel membrane obtained in 3) was immersed in N,N-dimethylformamide solution and acetone solution respectively, hot-pressed and dried at 60° C. for 16 h, and punched into a bacterial cellulose composite membrane with a diameter of 19 mm.

[0064] 5) Dissolve 0.4 g of succinonitrile (SN) and 0.08 g of ethylene carbonate (FEC) in 1.43 mL of 1,3-dioxolane (DOL). Add 0.861 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.05 g of lithium difluorooxalatoborate (LiDFOB) sequentially at 1000 rpm to produce a DOL-based precursor. Stirring is continued for 8 hours. Add 80 μL of the electrolyte precursor solution dropwise to each separator, heat to 60°C, and react for 12 hours to complete in-situ polymerization, thereby producing a solid electrolyte separator.

[0065] The mass proportion of succinonitrile in the solid electrolyte matrix (SN, FEC and DOL) was adjusted to 0, 0.05, 0.15, 0.25, 0.35, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.

[0066] Among them, SN with a content of 0.25 was used for subsequent main tests.

[0067] Example 2

[0068] This embodiment prepares a solid electrolyte membrane, and the specific process is as follows:

[0069] The material obtained in 2) of Example 1 was immersed in Zn 2+The mixture was placed in a methanol solution, shaken at a low speed on a shaker for 8 h, taken out, rinsed with methanol three times, placed in a 2-MI methanol solution, and allowed to stand for 24 h. The rest was the same as in Example 1.

[0070] Example 3

[0071] This embodiment prepares a solid electrolyte membrane, and the specific process is as follows:

[0072] The material obtained in 2) of Example 1 was immersed in Co 2+ The mixture was placed in a methanol solution, shaken at a low speed on a shaker for 8 h, taken out, rinsed with methanol three times, placed in a 2-MI methanol solution, and allowed to stand for 24 h. The rest was the same as in Example 1.

[0073] Example 4

[0074] This embodiment prepares a solid electrolyte membrane, and the specific process is as follows:

[0075] 2) in Example 1 was omitted, and the bacterial cellulose membrane obtained in 1) was directly subjected to the impregnation step, and the rest was the same as in Example 1.

[0076] Comparative Example 1

[0077] This comparative example prepared a diaphragm, and the specific process was as follows:

[0078] The purified bacterial cellulose membrane was directly punched into a diaphragm with a diameter of 19 mm, and the rest was the same as in Example 1.

[0079] Comparative Example 2

[0080] This comparative example prepared a diaphragm, and the specific process was as follows:

[0081] A commercial polyethylene (PP) film was punched into a diaphragm with a diameter of 19 mm, and the rest was the same as in Example 1.

[0082] Example 4

[0083] This embodiment prepares a lithium ion battery, and the specific process is as follows:

[0084] Preparation of positive electrode sheets: Dissolve polytetrafluoroethylene (PVDF) powder in an appropriate amount of NMP solvent to prepare a PVDF / NMP solution with a mass fraction of 1 wt%. Mix the active material LiFePO4, the conductive agent acetylene black and the binder PVDF in a mass ratio of 8:1:1, put them into a ball mill, and ball mill them at a speed of 300 rpm for 8 hours to obtain LiFePO4 slurry, which is coated on aluminum foil and vacuum dried at 120°C for 12 hours. The slurry is then punched into a positive electrode sheet with a diameter of 12 mm.

[0085] Assemble lithium-ion batteries: Use lithium metal sheets as negative electrodes and assemble in the order of positive electrode, separator, electrolyte precursor solution, and lithium metal negative electrode. The assembled batteries are sealed with a button battery sealing machine at a sealing pressure of 50kg / cm 2 The packaged 2025 button cell was placed at 60°C for 12 hours to complete in-situ polymerization.

[0086] Test Case

[0087] This test case tests the performance of lithium-ion batteries. The specific process is as follows:

[0088] The charge and discharge test of button cells at 2.5-4.2V was performed using the Blue Power Battery Test System to evaluate the rate performance and cycle performance of lithium-ion batteries.

[0089] The electrolyte membranes of Examples 1, 2 and Comparative Example 1 were sandwiched between two stainless steel (SS) electrodes to form a symmetrical cell of stainless steel / diaphragm / stainless steel. The electrochemical workstation CHI760E was used for measurement. The amplitude of the test was 5mV and the frequency range of the measurement was 0.1 to 10 6 Hz, and calculate the ionic conductivity of the solid electrolyte.

[0090] The ion migration number of the solid electrolyte membrane was determined by AC impedance and chronoamperometry. The solid electrolyte membrane was sandwiched between two lithium metal electrodes to assemble a Li / diaphragm / Li symmetrical battery. A small DC voltage DV (5mv) was applied to the battery to obtain a curve of the polarization current changing with time. The impedance spectrum of the battery before and after polarization was measured by AC impedance method to obtain the charge transfer resistance of the solid electrolyte membrane before and after polarization.

[0091] Figure 1 is the SEM image of bacterial cellulose in Comparative Example 1, Figure 1 It can be seen that bacterial cellulose has a three-dimensional nano-network skeleton.

[0092] Figure 2 This is the SEM image of bacterial cellulose directly loaded with MOF without coupling agent treatment in Example 4.

[0093] Figure 3 This is the SEM image of bacterial cellulose loaded with MOF after coupling agent treatment in Example 1. Figure 2 and Figure 3 It can be seen that although MOF can be loaded onto unsilanized BC, it is usually simply mixed with the BC and the loading is uneven. However, after silanization pretreatment, MOF can be evenly loaded onto the 3D network of BC.

[0094] Figure 4The XRD patterns of bacterial cellulose membranes in Example 1 and Comparative Example 1 are shown in FIG. Figure 2 It can be seen that the XRD pattern of the bacterial cellulose membrane material obtained in Example 1 Figure 8 The peaks at 0.0° and 8.4° are very consistent with the simulated MOF peaks. The peak of 22.62° in Example 1 and Comparative Example 1 represents the characteristic peak of bacterial cellulose. The above can illustrate the successful loading of MOF on bacterial cellulose.

[0095] Figure 5 These are the impedance spectra of the solid electrolyte membranes in Example 1, Example 2, Example 3, Example 4, Comparative Example 1, and Comparative Example 2 at room temperature. The data in Table 1 show that the ionic conductivity and lithium ion transference number of Example 1, Example 2, Example 3, and Example 4 at room temperature are higher than those of Comparative Example 1 and Comparative Example 2.

[0096] Table 1

[0097] Group Ionic conductivity (S / cm) Lithium ion migration number Comparative Example 1 <![CDATA[1.32×10 -5 ]]> 0.32 Comparative Example 2 <![CDATA[6.67×10 -5 ]]> 0.41 Example 1 <![CDATA[0.57×10 -3 ]]> 0.71 Example 2 <![CDATA[0.48×10 -3 ]]> 0.65 Example 3 <![CDATA[0.50×10 -3 ]]> 0.68 Example 4 <![CDATA[0.23×10 -4 ]]> 0.43

[0098] Figure 6 The curves of different contents of succinonitrile and ion conductivity of the solid electrolyte membrane in Example 1, Comparative Example 1 and Comparative Example 2 are shown. Figure 6 It can be seen that since the MOF uniformly loaded on the bacterial cellulose skeleton has a stronger interaction with SN, a small amount of succinonitrile can form an effective ion transport network in the bacterial cellulose, achieving a higher ionic conductivity.

[0099] Figure 7 The figure shows the test results of the solid electrolyte membrane simulated battery cycle performance in Example 1 and Comparative Examples 1 and 2. Figure 7 It can be seen that at the same current density of 170 mA / g, the capacity retention rate of the battery corresponding to the solid electrolyte membrane of Example 1 is 91.4% after 200 cycles at 1C, and the discharge specific capacity is 124.2 mAh g -1 , the cycle performance is much better than that of Comparative Example 1 and Comparative Example 2.

[0100] Figure 8 The figure is a rate diagram of the solid electrolyte membrane simulated battery charge and discharge process in Example 1, Comparative Example 1 and Comparative Example 2. Figure 8 It can be seen that as the current density increases, Example 1 always shows a higher specific capacity, and the discharge specific capacity of the battery is higher than that of Comparative Example 1 and Comparative Example 2, indicating that its performance is better than that of Comparative Example 1 and Comparative Example 2 at different current densities. When the current density returns to 0.2C, the reversible discharge capacity of Example 1 returns to the initial capacity of 159.6 mAh g -1 , demonstrating excellent rate capability and high electrochemical reversibility.

[0101] It can be seen that the preparation method of the solid electrolyte membrane provided by the present invention uses bacterial cellulose as a three-dimensional network skeleton. After pretreatment with a silane coupling agent, the metal-organic framework material is uniformly loaded on the nano-network structure of bacterial cellulose by respectively impregnating a metal ion solution and an organic ligand solution, and then the SN is precisely anchored to obtain a solid electrolyte membrane with an efficient ion transport channel. The assembled lithium-ion battery has high ionic conductivity, excellent rate performance and cycle performance.

[0102] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A porous diaphragm, characterized in that: include: A bacterial cellulose composite membrane, comprising a bacterial cellulose membrane and a metal organic framework loaded in the bacterial cellulose membrane; Succinonitrile, wherein the succinonitrile permeates the bacterial cellulose composite membrane.

2. The porous membrane according to claim 1, wherein: The metal organic framework in the bacterial cellulose composite membrane anchors the succinonitrile.

3. The porous membrane according to claim 1, wherein: The bacterial cellulose membrane is modified with an aminosilane surface coupling agent and then loaded with a metal organic framework.

4. The porous membrane according to claim 3, wherein: The porous membrane satisfies at least one of the following conditions: (I) the mass ratio of the bacterial cellulose membrane to the metal organic framework is 1.5-3:0.5-1; (II) the mass ratio of the bacterial cellulose membrane to succinonitrile is 0.4-2.5:0-1.1; (III) The mass ratio of the bacterial cellulose membrane to the aminosilane surface coupling agent is 0.4-3.5:0.1-0.

5.

5. The porous membrane according to claim 1, wherein: The metal organic framework includes at least one of Al-MOF, Zr-MOF, Zn-MOF, Co-MOF, Ce-MOF, Ti-MOF or Cu-MOF.

6. A solid electrolyte membrane, characterized in that: The porous diaphragm comprises the precursor of any one of claims 1 to 5 and a solid electrolyte.

7. The solid electrolyte membrane according to claim 6, characterized in that: The precursors of succinonitrile and solid electrolyte in the porous membrane are in situ polymerized on the bacterial cellulose composite membrane.

8. The solid electrolyte membrane according to claim 6, characterized in that: The precursor of the solid electrolyte includes the following preparation raw materials: polymer monomer, lithium salt, and functional additive.

9. A method for preparing the solid electrolyte membrane according to any one of claims 6 to 8, comprising the following steps: The solid electrolyte membrane is prepared by carrying out an in-situ polymerization reaction between succinonitrile and a precursor of a solid electrolyte on a bacterial cellulose composite membrane.

10. A solid-state battery comprising the solid electrolyte membrane according to any one of claims 6 to 8.

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