Preparation method of low-cost and high-safety composite polymer solid electrolyte

Abstract

The invention relates to a preparation method of a low-cost and high-safety composite polymer solid electrolyte, and belongs to the technical field of sodium ion semi-solid / solid batteries. The traditional PVDF-based solid electrolyte has the problems of low room-temperature ionic conductivity, insufficient mechanical strength, high interface impedance and the like. The composite solid electrolyte with a three-dimensional interpenetrating network structure is constructed by uniformly dispersing nanocellulose in a PVDF (polyvinylidene fluoride) matrix and combining a solvent casting process. The mechanical strength and the thermal stability of the electrolyte are remarkably improved through the nanocellulose, the interfacial compatibility between the electrolyte and an electrode is effectively improved through the synergistic effect of the nanocellulose and the PVDF, the interface impedance is reduced, and meanwhile, the growth of sodium dendrites is effectively inhibited. The preparation process is simple, the raw materials are environment-friendly, and the obtained electrolyte has high ionic conductivity, excellent mechanical properties and interface stability, is suitable for all-solid-state sodium metal batteries with high energy density and high safety, and has wide application prospects in the fields of electric automobiles and energy storage.

Description

Technical Field

[0001] The present invention belongs to the field of sodium ion semi-solid / solid state batteries, and particularly relates to a preparation method of a composite polymer solid electrolyte with low cost and high safety. Technical Background

[0002] With the rapid development of fields such as electric vehicles, portable electronic devices, and energy storage power stations, higher requirements are put forward for the energy density, safety, and cycle life of sodium ion batteries. However, traditional liquid electrolytes have safety hazards such as easy leakage, flammability, and explosiveness, which severely restrict the further development of sodium ion batteries. Polymer solid electrolytes can effectively overcome the defects of liquid electrolytes and have become the research focus of the next generation of high-energy density sodium batteries due to their high safety, good mechanical properties, and processability.

[0003] In polymer solid electrolytes, problems such as solid-solid contact, sodium dendrites, and ion transference number are fundamental issues affecting battery safety and stability. Solid-solid contact will hinder the migration of sodium ions during deposition, resulting in performance degradation. The formation of sodium dendrites will damage the solid electrolyte interface layer (SEI) formed between the solid electrolyte and the positive and negative electrode interfaces, and will continuously consume sodium metal, leading to irreversible deposition and the formation of "dead sodium", thus resulting in low cycle efficiency. Poor sodium ion conductivity will severely hinder the migration of Na + in polymer electrolytes. The unfixed sodium salt anions cause a concentration gradient of Na + during migration, thus causing local concentration polarization in the polymer, resulting in a decrease in the transference number of Na + and uneven Na + deposition.

[0004] Composite polymer solid electrolytes have good flexibility and are expected to be applied to semi-solid / solid state sodium ion batteries. Adding fillers to the polymer matrix is the main strategy to improve sodium ion transport. However, there are some challenges faced by traditional fillers; inorganic fillers have a high interfacial energy and are prone to agglomeration; organic fillers with high crystallinity will hinder the intrinsic conductivity of ions and severely hinder the migration of Na + ions.

[0005] Based on this, this patent uses polyvinylidene fluoride (PVDF) as the polymer backbone and nano-cellulose modified with NaCl (Na-NC) as the superionic conductor soft filler to prepare a composite polymer electrolyte membrane. Sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) and sodium salts form a dual sodium ion channel, which greatly improves the overall performance of the solid-state battery. Na-NC powder is prepared as a solid electrolyte filler by a simple solvent dissolution method to improve the ionic conductivity and ion transference number of the polymer solid electrolyte. The modified cellulose nanofibers not only significantly enhance the mechanical strength and thermal stability of the electrolyte as a reinforcing phase, but also the abundant hydroxyl groups on their surface can promote the dissociation of sodium salts and form a continuous ion transport channel, thus greatly increasing the room-temperature ionic conductivity. In addition, the synergistic effect between cellulose and PVDF effectively improves the interfacial compatibility between the electrolyte and the electrode, reduces the interfacial impedance, and inhibits the growth of sodium dendrites. The composite polymer solid electrolyte utilizes the van der Waals force, electrostatic interaction, and Lewis acid-base interaction between the filler and the polymer to enhance ion transport in the polymer matrix. The dipole moment interaction between the Na-NC and PVDF polymer chains produces a synergistic effect, significantly enhancing the Na + transport ability. This patent develops a flexible Na + dual-channel transport solid electrolyte (PDNC) by adding a superionic conductor soft filler to the PVDF polymer matrix. This electrolyte has good conductivity and shows satisfactory cycling performance in full-cell tests, demonstrating the feasibility of using soft fillers for semi-solid / solid-state sodium-ion batteries at room temperature. Summary of the Invention

[0006] The object of the present invention is to provide a preparation method of a low-cost and high-safety composite polymer solid electrolyte based on the defects of existing polymer solid electrolytes, such as insufficient flexibility, low sodium ion transference number, poor ionic conductivity, and short cycle life.

[0007] The present invention is achieved through the following technical solutions: Preferably, the Na-NC concentration of the PDNC solid electrolyte is 0.01~0.25 g mL -1 .

[0008] Preferably, the NaCl / DMAc concentration of the PDNC solid electrolyte is 0.1~0.22 mol L -1 .

[0009] Preferably, the mass ratio of PVDF:NaTFSI:Na-NC in the PDNC solid electrolyte is 3:2:0.01~0.2.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows; 1. The synthesis scheme of the PVDF-based polymer electrolyte provided by the present invention has lower cost and simple synthesis method. It can be used as the electrolyte of sodium-ion batteries, has great application prospects, and is expected to replace the use of liquid electrolytes.

[0011] 2. The PDNC solid electrolyte prepared by the present invention has the advantages of high ionic conductivity (6.62×10 -4 cm -1 ) at room temperature, high Na + transference number (~0.68), and wide electrochemical window (4.6 V). In addition, the Na-Na symmetric battery assembled with the solid electrolyte added with Na-NC filler can stably cycle for more than 1200 h at a current density of 0.1 mA cm -2 ; the assembled Na 2 / 3Ni 1 / 3 Mn 1 / 3 Ti 1 / 3 O2-Na full battery has a discharge specific capacity of 102 mAh g -1 at 2.5 - 4.3 V and 0.1 C, and the capacity retention rate can still reach 68% after cycling 1200 times at 0.3 C. It proves that Na-NC has great application potential as a superionic conductor soft filler in solid electrolytes.

[0012] 3. The raw materials used in the present invention are inexpensive and easily available, and the synthesis method is simple. It is expected to achieve large-scale production and has high practical value. Description of the Drawings

[0013] Figure 1 It is the X-ray diffraction pattern (XRD) of the Na-NC material in Example 1.

[0014] Figure 2 It is the X-ray diffraction pattern of the PDNC material in Example 1.

[0015] Figure 3 It is the scanning electron microscope photograph (SEM) of the PDNC material in Example 1.

[0016] Figure 4 It is the scanning electron microscope EDS energy spectrum of the PDNC material in Example 1.

[0017] Figure 5 It is the Raman spectrum of the PDNC material in Example 1.

[0018] Figure 6 It is the infrared spectrum of the PDNC material in Example 1.

[0019] Figure 7 It is the atomic force microscope test (AFM) of the PDNC material in Example 1.

[0020] Figure 8 For the alternating current impedance spectroscopy test (EIS) of the PDNC material in Example 1.

[0021] Figure 9 For the linear sweep voltammetry test (LSV) of the PDNC material in Example 1.

[0022] Figure 10 For the direct current polarization test (It) of the PDNC material in Example 1.

[0023] Figure 11 For the Tafel test (Tafel) of the PDNC material in Example 1.

[0024] Figure 12 For the critical current density (CCD) of the PDNC material in Example 1.

[0025] Figure 13 For the cycle performance test of the sodium symmetric battery with the PDNC material in Example 1.

[0026] Figure 14 For the PDNC material and Na 2 / 3 Ni 1 / 3 Mn 1 / 3 Ti 1 / 3 The rate performance of the button cell assembled with the O2 cathode material at different rates (0.1 C, 0.2 C, 0.3 C) at 2.5 - 4.3 V.

[0027] Figure 15 For the PDNC material and Na 2 / 3 Ni 1 / 3 Mn 1 / 3 Ti 1 / 3 The cycle performance of the button cell assembled with the O2 cathode material at 0.3 C.

[0028] Figure 16 For the PDNC material and Na 0.9 Li 0.1 Ni 0.3 Fe 0.1 Mn 0.6 The rate performance of the button cell assembled with the O2 cathode material at 1.5 - 4.2 V.

[0029] Figure 17 For the button cell assembled with the PDNC material and the Na8Fe4(P2O7)5 / PDNC / Na cathode material, at different rates at 1.5 - 4.2 V Figure 18For the PDNC material and NaMn in Example 1 0.95 Ti 0.05 A coin cell was assembled with the NaMnO₂ / PDNC / Na cathode material and tested at different rates in the voltage range of 1.5 - 4.3 V.

[0030] Figure 19 Schematic diagram of the sodium ion transport mechanism of the PDNC material in Example 1. Detailed implementation manners

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation procedures are given. However, the protection scope of the present invention is not limited to the following embodiments. Unless otherwise specified, the reagents used are commercially available from sources easily accessible to those skilled in the art.

[0032] Example 1. I. The following is used to illustrate the preparation of the polymer solid electrolyte. The material in this example is PDNC.

[0033] S1: Add NC (10 g) to DMAc (100 mL) and stir for 24 h. Then transfer the mixture to a vacuum oven and dry at 80 °C for 24 h to obtain NC powder.

[0034] S2: Prepare a NaCl / DMAc solution with a molar ratio of 0.17:1: Dissolve 1.9869 g of NaCl in 17.424 g of DMAc, add nanocellulose (NC, 3.882 g) to the solution, stir at room temperature for 24 h, and transfer to a 120 °C vacuum oven for drying for 24 h to obtain Na-NC powder for later use.

[0035] S3: Vacuum-dry PVDF and NaTFSI for 24 h to remove residual moisture. Then, add 0.5 g of PVDF, 0.33 g of NaTFSI, and 0.0375 g of Na-NC to 18 ml of DMAc, and mechanically stir at 500 rpm at room temperature for 24 h to obtain a homogeneous slurry.

[0036] S4: Pour the obtained homogeneous slurry into a polytetrafluoroethylene petri dish (diameter 50 - 70 mm), pre-dry at 40 - 60 °C for 2 - 4 h, then vacuum-dry at 80 - 100 °C for 12 - 24 h. Finally, transfer the petri dish to a glove box filled with argon (the concentrations of O₂ and H₂O are lower than 0.01 ppm). Peel the dried film from the polytetrafluoroethylene petri dish to obtain the PDNC polymer solid electrolyte.

[0037] The obtained composite electrolyte membrane was subjected to the following physical characterizations: AsFigure 1 As shown, the peak at 22.5° in the XRD shows a significant decrease, indicating that the crystallinity of the modified Na-NC decreases, which is beneficial to the + transport of Na ions. As Figure 2 shown, the XRD shows that the main peak does not disappear, indicating that the PDNC polymer solid electrolyte has been successfully prepared. As Figure 3 shown, SEM shows that the surface of the prepared PDNC electrolyte is uniform and smooth, and no agglomeration phenomenon appears. As Figure 4 shown, the Mapping of the solid electrolyte shows that various elements in the electrolyte are evenly distributed. As Figure 5 shown, the Raman spectrum shows an enhanced peak of TFSI ions, proving that Na-NC interacts with anions and accelerates the + migration of Na. As Figure 6 shown, the infrared spectrum (1666 cm -1 , 1134 cm -1 ) shows the peaks of C=O and C-O, proving that the PVDF in the material still maintains its original structure. As Figure 7 shown, the atomic force microscope image shows that the surface of the PDNC electrolyte is smooth and flat. As Figure 19 shown, the + transport mechanism of Na in the PDNC electrolyte.

[0038] Second, the obtained composite electrolyte membrane is assembled into a button cell for electrochemical performance testing: (1) Assembly and testing of SS / PDNC / SS battery The above-obtained composite electrolyte membrane is cut into circular pieces with a radius of 8 mm for assembling a sodium ion symmetric battery. The button full cell is assembled using a CR2032 type, and is assembled in the order of the negative electrode case, SS (steel sheet), solid electrolyte, SS sheet, gasket, spring sheet, and positive electrode case, and sealed with a sealing machine under a pressure of 50 MPa. The entire button cell assembly process needs to be completed in a glove box under an argon atmosphere.

[0039] (1) At 25 °C, an electrochemical workstation is used to perform electrochemical impedance spectroscopy (EIS) testing, and the following formula is used for calculation:

[0040] where σ is the ionic conductivity, L is the thickness of the electrolyte membrane, R is the resistance value, and S is the area of the electrolyte membrane. The test results are as Figure 8 shown in the figure. The impedance of the PDNC-1 electrolyte at 25 °C is 12 Ω.

[0041] (2) Assembly and testing of SS / PDNC / Na battery The obtained composite electrolyte membrane was cut into circular pieces with a radius of 8 mm for assembling sodium-ion symmetric batteries. The button full battery was assembled using the CR2032 type and assembled in the order of the negative electrode case, SS sheet, electrolyte, Na sheet, gasket, shrapnel, and positive electrode case, and sealed with a sealing machine at a pressure of 50 MPa. The entire button battery assembly process needs to be completed in a glove box under an argon atmosphere.

[0042] The linear sweep voltammetry (LSV) was used to evaluate the electrochemical window of PDNC. From Figure 9 it can be seen that the electrochemical window of PDNC-1 can reach 4.85 V at 25 °C, 0.1 mV s -1 .

[0043] (3) Assembly and testing of Na / PDNC / Na batteries The obtained composite electrolyte membrane was cut into circular pieces with a radius of 8 mm for assembling sodium-ion symmetric batteries. The button full battery was assembled using the CR2032 type and assembled in the order of the negative electrode case, Na sheet, electrolyte, Na sheet, gasket, shrapnel, and positive electrode case, and sealed with a sealing machine at a pressure of 50 MPa. The entire button battery assembly process needs to be completed in a glove box under an argon atmosphere.

[0044] Measure the Na + transfer number (t Na+ ) of PDNC, and obtain the initial current I 0 and the steady-state value I ss through DC polarization measurement. The value of t Na+ is calculated by the Bruce-Vincent-Evans equation.

[0045]

[0046] Where R 0 and R ss are the initial resistance and steady-state interfacial resistance obtained from EIS before and after polarization, respectively. The voltage amplitude is set to 10 mV. From Figure 10 it can be seen that the sodium-ion transference number of PDNC-1 can reach up to 0.687 at 25 °C.

[0047] (4) Assemble the Na / PDNC / Na battery and measure its Tafel curve at -0.5 V - 0.5 V. From Figure 11 it can be seen that the exchange current density is 5.13x10 -2 mA cm -2 at 25 °C.

[0048] (5) Assemble the Na / PDNC / Na battery and measure the critical current density (CCD). As can be seen from Figure 12 , the critical current density can reach up to 1.5 mA cm at 25 °C -2 , showing a long cycle life.

[0049] (6) Assemble the Na / PDNC / Na battery and measure the cycling performance of the symmetric battery. As can be seen from Figure 13 , at 25 °C and 0.1 mA cm -2 , the button cell can cycle for 1500 h.

[0050] (7) Assembly and testing of the Na 2 / 3 Ni 1 / 3 Mn 1 / 3 Ti 1 / 3 O2 / PDNC / Na full cell For the assembly of the button full cell, the CR2032 type is used. Assemble in the order of the negative electrode case, Na sheet, solid electrolyte, Na 2 / 3 Ni 1 / 3 Mn 1 / 3Ti 1 / 3 O2 positive electrode sheet, gasket, spring piece and positive electrode case, and seal with a sealing machine under a pressure of 50 MPa. The entire assembly process of the button cell needs to be completed in a glove box under an argon atmosphere. In the present invention, all electrochemical performance tests of the full cells are carried out at room temperature.

[0051] Test the electrochemical performance of the assembled full cell at different rates (0.1 C, 0.2 C, 0.3 C) in the range of 2.5 - 4.3 V. The results are as Figure 14 shown. The difference in specific capacity of the material at different current densities is small, indicating that the battery has excellent rate performance (8) Assemble the Na 2 / 3 Ni 1 / 3 Mn 1 / 3 Ti 1 / 3 O2 / PDNC / Na full cell and test the cycling performance at 2.5 - 4.3 V and 0.3 C as Figure 15 shown. After the full cell cycles 1200 times, the capacity retention rate is 68.15%, showing excellent long - cycle performance.

[0052] (9) Assemble the Na 0.9 Li 0.1 Ni 0.3 Fe 0.1 Mn 0.6 O2 / PDNC / Na full cell and test the rate performance at different current densities (0.1 C, 0.2 C, 0.3 C, 0.4 C, 0.5 C) at 1.5 - 4.3 V. The results are asFigure 16 As shown, Na 0.9 Li 0.1 Ni 0.3 Fe 0.1 Mn 0.6 The Na / O₂ / PDNC / Na all - cell exhibits excellent rate performance.

[0053] (10) Assemble the Na₈Fe₄(P₂O₇)₅ / PDNC / Na all - cell and test its rate performance at different current densities (0.1 C, 0.2 C, 0.3 C, 0.4 C, 0.5 C) in the voltage range of 1.5 - 4.2 V. As Figure 17 shown, the Na₈Fe₄(P₂O₇)₅ / PDNC / Na all - cell exhibits excellent rate performance.

[0054] (11) Assemble the NaMn 0.95 Ti 0.05 O₂ / PDNC / Na all - cell and test its rate performance at different current densities (0.1 C, 0.2 C, 0.3 C, 0.4 C, 0.5 C) at 1.5 - 4.3 V. As Figure 18 shown, the NaMn 0.95 Ti 0.05 O₂ / PDNC / Na all - cell exhibits excellent rate performance.

[0055] Tests 9 - 11 show that the PDNC polymer solid electrolyte has universality.

[0056] Example 2: The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na - NC is different. In Example 2, the mass ratio of PVDF to Na - NC is 1:0.015.

[0057] Example 3: The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na - NC is different. In Example 3, the mass ratio of PVDF to Na - NC is 1:0.035.

[0058] Example 4: The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na - NC is different. In Example 4, the mass ratio of PVDF to Na - NC is 1:0.055.

[0059] Example 5. The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na-NC is different. In Example 5, the mass ratio of PVDF to Na-NC is 1:0.07.

[0060] Example 6. The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na-NC is different. In Example 6, the mass ratio of PVDF to Na-NC is 1:0.15.

[0061] Example 7. The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na-NC is different. In Example 7, the mass ratio of PVDF to Na-NC is 1:0.175.

[0062] Example 8. The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na-NC is different. In Example 8, the mass ratio of PVDF to Na-NC is 1:0.22.

[0063] Example 9. The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na-NC is different. In Example 9, the mass ratio of PVDF to Na-NC is 1:0.25.

[0064] Example 10. The preparation method and reaction conditions of the composite polymer solid electrolyte PDNC are the same as those in Example 1, except that the mass ratio of the polymer PVDF substrate to the soft filler Na-NC is different. In Example 10, the mass ratio of PVDF to Na-NC is 1:0.30.

[0065] In Comparative Example 1, no nanocellulose is added. Except for this, all other conditions and steps are the same as those in Example 1. No nanocellulose is added in this comparative example.

[0066] In Comparative Example 2, no nanocellulose is added. Except for this, all other conditions and steps are the same as those in Example 1. In this comparative example, commercially available nanocellulose is added.

[0067] Table 1 Performance data of each example and comparative example <![CDATA[Room temperature sodium ion conductivity (mS cm -2 )]]> Sodium ion transference number Example 1 <![CDATA[6.62x10 -4 > 0.68 Example 2 <![CDATA[1.45x10 -4 > 0.45 Example 3 <![CDATA[1.73x10 -4 > 0.46 Example 4 <![CDATA[4.61x10 -4 > 0.57 Example 5 <![CDATA[4.84x10 -4 > 0.58 Example 6 <![CDATA[5.42x10 -4 > 0.63 Example 7 <![CDATA[5.33x10 -4 > 0.59 Example 8 <![CDATA[5.21x10 -4 > 0.53 Example 9 <![CDATA[5.06x10 -4 > 0.49 Example 10 <![CDATA[4.92x10 -4 > 0.46 Comparative Example 1 <![CDATA[5.92x10 -5 > 0.22 Comparative Example 2 <![CDATA[2.92x10 -4 > 0.34 The process method provided by this discovery can prepare PDNC polymer solid electrolytes with different proportions by adding appropriate additives and sodium salts according to the ratio with PVDF as the substrate. Table 1 shows the room-temperature conductivity and sodium ion transference number of polymer solid electrolytes with different proportions that can be prepared. Any simple modification of the method described in the present invention to prepare PDNC polymer solid electrolyte materials other than those listed in Table 1 still falls within the technical solution of the present invention.

[0068] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A preparation method of a low-cost and high-safety composite polymer solid electrolyte: characterized in that, It includes the following steps: S1: Prepare dry nanocellulose (NC) by solvent dissolution method: Add NC to N,N-dimethylformamide (DMAc) (0.01 - 0.1 g mL -1 ), then transfer the mixture to a vacuum oven and dry it at 100 - 120 °C for 15 - 24 h to obtain NC powder for later use; S2: Prepare Na-NC powder: First, prepare a mixed solution of NaCl and DMAc (molar ratio 0.01 - 0.17:1). Subsequently, add NC powder to this solution, and the concentration of NC in the mixed solution is 0.01 - 0.1 g mL⁻¹. Stir the mixed system at room temperature for 24 h, and finally obtain the Na-NC product through vacuum drying. S3: Dissolve PVDF in DMAc, add sodium salt (concentration: 0.1 - 1.0 mol mL -1 ), and Na-NC (7.5% - 30% based on PVDF), and stir at room temperature for 15 - 24 h until completely dissolved to form a precursor solution for standby; S4: Cast the precursor solution into a polytetrafluoroethylene petri dish, pre-dry it at 40 - 60 °C for 2 - 4 h, then vacuum dry it at 80 - 100 °C for 12 - 24 h. Finally, transfer it to a glove box filled with argon (the concentrations of O2 and H2O are lower than 0.01 ppm) and dry it for 12 - 24 h before use. Peel the formed polymer electrolyte membrane (PDNC) from the polytetrafluoroethylene to obtain the PDNC polymer solid electrolyte.

2. The preparation method of a low-cost and high-safety composite polymer solid electrolyte according to claim 1, characterized in that, The sodium salt is selected from one or more mixtures of sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), sodium hexafluorophosphate (NaPF6), and sodium bis(fluorosulfonyl)imide (NaFSI).

3. The preparation method of a low-cost and high-safety composite polymer solid electrolyte according to claim 1, characterized in that, The polymer includes one or more mixtures of PVDF, PEO, and PVDF-HFP.

4. The preparation method of a low-cost and high-safety composite polymer solid electrolyte according to claim 1, characterized in that, The thickness of the polymer solid electrolyte membrane is 10 - 120 μm.

5. A polymer solid electrolyte membrane, characterized in that, It includes the preparation method of any one of the low-cost and high-safety composite polymer solid electrolytes described in Claims 1 - 4 and its application in semi-solid / solid sodium-ion batteries.

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