Inorganic-organic composite solid electrolyte membrane and method for manufacturing the same
By using modified PEO and mixed solvents, an inorganic-organic composite solid electrolyte membrane was prepared, which solved the problems of PEO decomposition and uneven dispersion in polar solvents and improved the ionic conductivity and lithium-ion transport performance of the electrolyte membrane.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU MATERIAL IND TECH INSTITUE
- Filing Date
- 2026-01-04
- Publication Date
- 2026-05-26
AI Technical Summary
In the wet preparation of sulfide solid electrolyte membranes, PEO is easily soluble in polar solvents, which leads to the decomposition of the sulfide electrolyte structure and a decrease in performance. In addition, the uneven dispersion of PEO affects the powder sedimentation and slurry uniformity.
Methyl-terminated polyethylene oxide was used to modify PEO, and Li3PO4 was added to a mixed solvent of anisole and tetrahydrofuran to promote the dispersion of PEO in the solvent and form a homogeneous slurry, thus preparing an inorganic-organic composite solid electrolyte membrane.
It improves the ionic conductivity of sulfide solid electrolytes, inhibits PEO degradation, increases lithium-ion transport rate, and enhances the ionic conductivity of composite membranes.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrolyte membrane technology, specifically relating to an inorganic-organic composite solid electrolyte membrane and its preparation method. Background Technology
[0002] Polyethylene oxide (PEO), as a polymer electrolyte, is an ideal choice for preparing sulfide solid electrolyte membranes. However, in the wet process for preparing sulfide solid electrolyte membranes, PEO needs to be dissolved in a solvent. PEO is a polar material and readily soluble in polar solvents. However, the PS4 in the sulfide electrolyte structure... 3- PEO is easily attacked by polar groups, leading to structural decomposition and performance degradation. A common approach in the field to address this issue is to change the type of solvent, for example, dissolving PEO in anisole. However, the hydrogen bonds or polar interactions between anisole and the ether oxygen atoms on the PEO chain are relatively weak, failing to effectively disperse PEO molecules in the solvent. This affects the encapsulation and dispersion effect of PEO on sulfide solid electrolytes, causing powder sedimentation and preventing the formation of a uniform slurry.
[0003] It is necessary to provide an inorganic-organic composite solid electrolyte membrane and its preparation method to solve the above problems. Summary of the Invention
[0004] This invention provides an inorganic-organic composite solid electrolyte membrane and its preparation method. The method involves modifying PEO by methyl end-capping to mitigate its interaction with sulfide electrolytes, and adding tetrahydrofuran solvent to weaken the interaction between the ether oxygen atoms on the PEO chain and anisole, thus promoting the dispersion of PEO in the mixed solvent. This results in a homogeneous slurry, which in turn yields a uniformly coated inorganic-organic composite solid electrolyte membrane, effectively solving at least one of the technical problems mentioned in the background art.
[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows: A method for preparing an inorganic-organic composite solid electrolyte membrane includes the following steps: Step S1: Dissolve a certain mass of methyl-terminated polyethylene oxide in a mixed solvent of anisole and tetrahydrofuran, and then add Li3PO4 at 25-50% of the mass of methyl-terminated polyethylene oxide. After complete dissolution, a mixed solution with a methyl-terminated polyethylene oxide content of 0.04-0.12 g / mL is formed. Step S2: Under a pure argon protective atmosphere, add sulfide solid electrolyte powder to the mixed solution at 88-96% of the mass of methyl-terminated polyethylene oxide, stir evenly and degas to obtain a homogeneous mixed slurry. Step S3: An inorganic-organic composite solid electrolyte membrane is prepared using a wet membrane-making process with a mixed slurry as the raw material.
[0006] As a preferred improvement, methyl-terminated polyethylene oxide has a weight-average molecular weight of 10,000 to 1,000,000.
[0007] As a preferred improvement, the volume percentage of anisole in the mixed solvent is 20%-80%.
[0008] As a preferred improvement, in step S1, the dissolution process is carried out at a temperature of 70-75°C, accompanied by stirring at a stirring rate of 800-2000 rpm.
[0009] As a preferred improvement, the sulfide solid electrolyte is Li. 9.54 Si 1.044 Ge 0.696 P 1.44 S 11.1 Br 0. 3O 0.6 and Li 9.9 SnP2S 11.9 Cl 0.1 At least one of them.
[0010] As a preferred improvement, the "stirring and degassing" step S2 specifically includes the following process: stirring at 2500-3000 rpm for 8-10 minutes using a high-speed homogenizer, and then stirring at 800-1000 rpm for 3-5 minutes to degas.
[0011] As a preferred improvement, step S3 specifically includes the following steps: Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0012] An inorganic-organic composite solid electrolyte membrane is prepared using the above-described preparation method.
[0013] As a preferred improvement, the inorganic-organic composite solid electrolyte membrane has an ionic conductivity of (0.5-1.2)×10⁻⁶. -3 S / cm.
[0014] The beneficial effects of this invention are as follows: This invention uses anisole and tetrahydrofuran as a mixed solvent to dissolve methyl-terminated PEO. Tetrahydrofuran can weaken the interaction between the ether oxygen atoms on the PEO chain and anisole, promoting the dispersion of PEO in the mixed solvent and improving the sedimentation of sulfide powder caused by the interaction between the ether oxygen atoms on the PEO chain and anisole in pure anisole solvent, thus promoting the formation of a homogeneous coating slurry. Methyl-terminated polyethylene oxide can not only improve the loss of ionic conductivity after the sulfide solid electrolyte and the non-ion-conducting binder are combined into a film, but its methyl-termination can also inhibit the degradation effect of polyethylene oxide on the sulfide solid electrolyte, better preserving the high-performance characteristics of the sulfide. In addition, the addition of Li3PO4 increases the lithium ion transport rate in polyethylene oxide, thereby improving the ionic conductivity of the composite solid electrolyte membrane. Detailed Implementation
[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.
[0016] This embodiment provides a method for preparing an inorganic-organic composite solid electrolyte membrane, comprising the following steps: Step S1: Dissolve a certain mass of methyl-terminated polyethylene oxide in a mixed solvent of anisole and tetrahydrofuran, and then add Li3PO4 at 25-50% of the mass of methyl-terminated polyethylene oxide. After complete dissolution, a mixed solution with a methyl-terminated polyethylene oxide content of 0.04-0.12 g / mL is formed. Step S2: Under a pure argon protective atmosphere, add sulfide solid electrolyte powder to the mixed solution at 88-96% of the mass of methyl-terminated polyethylene oxide, stir evenly and degas to obtain a homogeneous mixed slurry. Step S3: An inorganic-organic composite solid electrolyte membrane is prepared using a wet membrane-making process with a mixed slurry as the raw material.
[0017] The weight-average molecular weight of methyl-terminated polyethylene oxide is 10,000 to 1,000,000; in the mixed solvent, the volume percentage of anisole is 20% to 80%.
[0018] In step S1, the dissolution process is carried out at a temperature of 70-75℃, accompanied by stirring at a speed of 800-2000 rpm.
[0019] The sulfide solid electrolyte was chosen to be Li 9.54 Si 1.044 Ge 0.696 P 1.44 S11.1 Br 0.3 O 0.6 and Li 9.9 SnP2S 11.9 Cl 0.1 At least one of them.
[0020] Step S2, “stirring and degassing”, specifically includes the following process: using a high-speed homogenizer to stir at 2500-3000 rpm for 8-10 minutes, and then stirring at 800-1000 rpm for 3-5 minutes to degas.
[0021] Step S3 specifically includes the following steps: Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0022] The above wet film-forming process is performed on a flatbed coating machine.
[0023] In a mixed solvent of anisole and tetrahydrofuran, tetrahydrofuran can weaken the interaction between the ether oxygen atoms on the PEO chain and anisole, promoting the dispersion of PEO in the mixed solvent and improving the sedimentation of sulfide powder caused by the interaction between the ether oxygen atoms on the PEO chain and anisole in pure anisole solvent, thus promoting the formation of a homogeneous coating slurry. Methyl-terminated polyethylene oxide can not only improve the loss of ionic conductivity after the sulfide solid electrolyte and the non-ion-conducting binder are combined into a film, but its methyl termination can also inhibit the degradation effect of polyethylene oxide on the sulfide solid electrolyte, better preserving the high-performance characteristics of sulfides. The addition of Li3PO4 can increase the lithium ion transport rate in polyethylene oxide, thereby improving the ionic conductivity of the composite solid electrolyte membrane.
[0024] The preparation route of methyl-terminated polyethylene oxide is as follows, which belongs to the prior art in this field.
[0025] .
[0026] This embodiment also provides an inorganic-organic composite solid electrolyte membrane, prepared using the above-described preparation method. The inorganic-organic composite solid electrolyte membrane has an ionic conductivity of (0.5-1.2)×10⁻⁶. -3 S / cm.
[0027] The technical solution of this invention will be described in detail below with reference to different embodiments.
[0028] Example 1 This embodiment provides a method for preparing an inorganic-organic composite solid electrolyte membrane, comprising the following steps: 0.08 g of methyl-terminated polyethylene oxide with a weight average molecular weight of 300,000 was dissolved in 2 mL of mixed solvent, and then 0.02 g of Li3PO4 was added to form a mixed solution with a polyethylene oxide content of 0.03 g / mL. The volume percentage of anisole in the mixed solvent was 60% and the volume percentage of tetrahydrofuran was 40%. Under a pure argon protective atmosphere, 1.92 g of sulfide solid electrolyte Li 9.54 Si 1.044 Ge 0.696 P 1.44 S 11.1 Br 0. 3O 0.6 The powder was added to the mixed solution and stirred at 2500 rpm for 8 minutes using a high-speed homogenizer, followed by degassing at 1000 rpm for 3 minutes to obtain a homogeneous mixed slurry. Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0029] Example 2 This embodiment provides a method for preparing an inorganic-organic composite solid electrolyte membrane, comprising the following steps: 0.08 g of methyl-terminated polyethylene oxide with a weight average molecular weight of 300,000 was dissolved in 2 mL of a mixed solvent, and then 0.02 g of Li3PO4 was added to form a mixed solution with a polyethylene oxide content of 0.04 g / mL; the volume percentage of anisole in the mixed solvent was 60%, and the volume percentage of tetrahydrofuran was 40%. Under a pure argon protective atmosphere, 1.92 g of sulfide solid electrolyte Li 9.9 SnP2S 11.9 Cl 0.1 The powder was added to the mixed solution and stirred at 2500 rpm for 8 minutes using a high-speed homogenizer, followed by degassing at 1000 rpm for 3 minutes to obtain a homogeneous mixed slurry. Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0030] Example 3 This embodiment provides a method for preparing an inorganic-organic composite solid electrolyte membrane, comprising the following steps: 0.24 g of methyl-terminated polyethylene oxide with a weight average molecular weight of 300,000 was dissolved in 2 mL of mixed solvent, and then 0.12 g of Li3PO4 was added to form a mixed solution with a polyethylene oxide content of 0.12 g / mL. The volume percentage of anisole in the mixed solvent was 50%, and the volume percentage of tetrahydrofuran was 50%. Under a pure argon protective atmosphere, 1.76 g of sulfide solid electrolyte Li 9.54 Si 1.044 Ge 0.696 P 1.44 S 11.1 Br 0.3 O 0.6 The powder was added to the mixed solution and stirred at 2500 rpm for 8 minutes using a high-speed homogenizer, followed by degassing at 1000 rpm for 3 minutes to obtain a homogeneous mixed slurry. Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0031] Example 4 This embodiment provides a method for preparing an inorganic-organic composite solid electrolyte membrane, comprising the following steps: 0.24 g of methyl-terminated polyethylene oxide with a weight average molecular weight of 300,000 was dissolved in 2 mL of a mixed solvent, and then 0.12 g of Li3PO4 was added to form a mixed solution with a polyethylene oxide content of 0.12 g / mL; the volume percentage of anisole in the mixed solvent was 50%, and the volume percentage of tetrahydrofuran was 50%. Under a pure argon protective atmosphere, 1.76 g of solid sulfide Li was electrolyzed. 9.9 SnP2S 11.9 Cl0.1 The powder was added to the mixed solution and stirred at 2500 rpm for 8 minutes using a high-speed homogenizer, followed by degassing at 1000 rpm for 3 minutes to obtain a homogeneous mixed slurry. Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0032] Comparative Example This embodiment provides a method for preparing a solid electrolyte membrane, including the following steps: Dissolve 0.08 g of polyethylene oxide with a weight average molecular weight of 300,000 in 2 mL of anisole to form a solution with a polyethylene oxide content of 0.04 g / mL. Under a pure argon protective atmosphere, 1.92 g of sulfide solid electrolytic Li was weighed. 9.54 Si 1.044 Ge 0.696 P 1.44 S 11.1 Br 0. 3O 0.6 The powder was added to the solution and stirred at 2500 rpm for 8 minutes using a high-speed homogenizer, followed by degassing at 1000 rpm for 3 minutes to obtain a homogeneous mixed slurry. Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
[0033] The ionic conductivity of the samples obtained in Examples 1-4 and the comparative examples was measured. The measurement process was as follows: The electrolyte membrane was cut into 10 mm diameter discs. A test battery was assembled using a mold lined with polyetheretherketone (PEEK). After being pressurized to 150 MPa and held for 3 minutes, the battery was transferred to a constant temperature chamber and incubated at 40 °C for 2 hours. Electrochemical impedance spectroscopy (EIS) was then performed using an electrochemical workstation. The ionic conductivity is shown in Table 1. Table 1. Ionic conductivity of each sample As can be seen from Table 1, the ionic conductivity of Examples 1-4 is significantly higher than that of the comparative examples, indicating that the inorganic-organic composite solid electrolyte membrane prepared by the method of the present invention can effectively improve the ionic conductivity.
[0034] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit of the present invention, and all of these forms are within the protection scope of the present invention.
Claims
1. A method for preparing an inorganic-organic composite solid electrolyte membrane, characterized in that, Includes the following steps: Step S1: Dissolve a certain mass of methyl-terminated polyethylene oxide in a mixed solvent of anisole and tetrahydrofuran, and then add Li3PO4 at 25-50% of the mass of methyl-terminated polyethylene oxide. After complete dissolution, a mixed solution with a methyl-terminated polyethylene oxide content of 0.04-0.12 g / mL is formed. Step S2: Under a pure argon protective atmosphere, sulfide solid electrolyte powder is added to the mixed solution at a mass ratio of methyl-terminated polyethylene oxide to sulfide solid electrolyte of (4:96)-(12:88), stirred evenly and degassed to obtain a homogeneous mixed slurry. Step S3: An inorganic-organic composite solid electrolyte membrane is prepared using a wet membrane-making process with a mixed slurry as the raw material.
2. The method for preparing the inorganic-organic composite solid electrolyte membrane according to claim 1, characterized in that, The weight-average molecular weight of methyl-terminated polyethylene oxide is 10,000 to 1,000,000.
3. The method for preparing the inorganic-organic composite solid electrolyte membrane according to claim 1, characterized in that, In mixed solvents, the volume percentage of anisole is 20%-80%.
4. The method for preparing the inorganic-organic composite solid electrolyte membrane according to claim 1, characterized in that, In step S1, the dissolution process is carried out at a temperature of 70-75℃, accompanied by stirring at a speed of 800-2000 rpm.
5. The method for preparing the inorganic-organic composite solid electrolyte membrane according to claim 1, characterized in that, The sulfide solid electrolyte was chosen to be Li 9.54 Si 1.044 Ge 0.696 P 1.44 S 11.1 Br 0.3 O 0.6 and Li 9.9 SnP2S 11.9 Cl 0.1 At least one of them.
6. The method for preparing the inorganic-organic composite solid electrolyte membrane according to claim 1, characterized in that, Step S2, "stirring evenly and degassing", specifically includes the following process: use a high-speed homogenizer to stir at 2500-3000 rpm for 8-10 minutes, and then stir at 800-1000 rpm for 3-5 minutes to degas.
7. The method for preparing the inorganic-organic composite solid electrolyte membrane according to claim 1, characterized in that, Step S3 specifically includes the following steps: Under a pure argon protective atmosphere, using aluminum foil as a substrate, a 300mm thick coating blade is used to uniformly coat the mixed slurry onto the aluminum foil substrate at a speed of 2mm / s. The substrate is then heated to 50℃ and dried for 20 minutes to obtain a pre-formed film. The film is then placed in a vacuum drying oven and baked at 60℃ for 720 minutes to completely remove the solvent. After the film is compacted by an electric roller press, the aluminum foil substrate is peeled off to obtain an inorganic-organic composite solid electrolyte membrane.
8. An inorganic-organic composite solid electrolyte membrane, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.
9. The inorganic-organic composite solid electrolyte membrane according to claim 8, characterized in that, The inorganic-organic composite solid electrolyte membrane has an ionic conductivity of (0.5-1.2)×10⁻⁶. -3 S / cm.