A light-driven solid-state electrolyte membrane and integrated flexible light-assisted solid sodium metal battery based thereon

Abstract

The application provides a light-driven solid-state electrolyte membrane and an integrated flexible light-assisted solid-state sodium metal battery based on the same, and belongs to the technical field of batteries. The battery comprises a light-driven solid-state electrolyte membrane and a photoelectrochemical storage positive electrode. The light-driven solid-state electrolyte membrane comprises polyethylene oxide, a heterojunction filler, a wood fiber soft filler and a sodium salt, wherein the heterojunction filler is a composite material of copper oxide and indium oxide. The photoelectrochemical storage positive electrode comprises an indium selenium oxide film, titanium dioxide and sodium vanadium phosphate. By incorporating a trace amount of heterojunction into the polyethylene oxide electrolyte, the application utilizes the photogenerated electric field generated by the light-driven mechanism to reduce the interface impedance, effectively improves the ionic conductivity and the sodium ion transfer number; and in combination with the energy level matched photoelectrochemical storage positive electrode, the application maximizes the use of photogenerated carriers and enhances the interface compatibility between the electrolyte and the positive electrode; and the battery assembled by the application exhibits excellent cycle stability.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a light-driven solid electrolyte membrane and an integrated flexible light-assisted solid sodium metal battery based thereon. Background Technology

[0002] Photo-assisted rechargeable sodium metal batteries offer advantages such as high energy efficiency, lightweight structure, and simplified design, which are crucial for the growing demand in portable electronics. However, addressing the intrinsic safety issues of liquid electrolytes and the slow reaction kinetics in existing photoelectrochemical storage cathodes remains a significant challenge.

[0003] To overcome the inherent limitations of liquid-based photo-assisted sodium metal batteries, recent research has shifted towards the development of photo-assisted solid-state sodium metal batteries. Polyethylene oxide (PEO) composite solid-state electrolytes effectively meet the requirements due to their high flexibility, ease of processing, and good interfacial compatibility; however, their low ionic conductivity and interfacial stability limit their further practical application. Adding heterojunction fillers to PEO can improve its low ionic conductivity. For example, Kang et al. prepared Bi₄Ti₃O₄... 12 The addition of BiOBr heterojunction fillers to polyethylene oxide improves ionic conductivity (Adv. Funct. Mater. 2023, 33, 2307263. DOI: 10.1002 / adfm.202307263). However, these heterojunction fillers lack other photocatalytic or other functional properties to further enhance ionic conductivity, thus failing to meet practical application requirements.

[0004] Meanwhile, although the photo-assisted mechanism has been initially applied in photo-assisted solid sodium metal batteries, the photoelectric cathode still needs to be properly matched and integrated into a single design to better improve the sodium ion storage kinetics in the photo-assisted mode, thereby achieving rapid sodium ion storage and excellent cycle performance. Summary of the Invention

[0005] This invention provides an integrated, flexible, light-assisted solid-state sodium metal battery by developing a regulation mechanism for photocatalytically active heterojunction fillers based on a screening strategy and combining it with a coupled photoelectrochemical storage cathode. The invention utilizes the heterojunction to generate a strong and stable photogenerated electric field via light, accelerating the dissociation of sodium salts and reducing interfacial impedance, thereby effectively improving ionic conductivity and sodium ion transfer number. Simultaneously, the solid-state electrolyte, optimized for pairing with the photoelectrochemical storage cathode based on the energy level matching principle, achieves high integration, improves electrolyte / cathode interface compatibility, and significantly enhances sodium ion storage kinetics in light-assisted mode, thus achieving rapid sodium ion storage and excellent cycling performance.

[0006] The objective of this invention can be achieved through the following methods:

[0007] This invention first discloses a light-driven solid electrolyte membrane for light-assisted solid sodium metal batteries, wherein the light-driven solid electrolyte membrane is made from polyethylene oxide, heterojunction filler, lignocellulose soft filler and sodium salt as raw materials.

[0008] Furthermore, the content of the heterojunction filler accounts for 1%-20% of the total mass of the solid electrolyte membrane, the content of the lignocellulose soft filler accounts for 0.5%-3% of the total mass of the solid electrolyte membrane, and the balance is the polymer matrix material polyethylene oxide and sodium salt (molar ratio: [EO]:[Na]=18:1).

[0009] Further, the heterojunction filler is a composite material of copper oxide and indium oxide, prepared by adding indium nitrate hexahydrate, copper nitrate trihydrate, 4,5-imidazolium dicarboxylic acid, and benzimidazole in a molar ratio of 0.08:0.034:0.512:(1.5-2.0) to dimethylformamide and ultrasonically stirring until dissolved. The resulting reaction mixture is heated to 90-120°C and maintained under continuous stirring for 2-10 hours, then centrifuged, dried, and annealed in a tube furnace filled with argon atmosphere at 400-600°C to obtain the heterojunction filler. Most preferably, the reaction mixture is heated in an oil bath at 120°C for 4 hours. The annealing temperature is 500°C, held for 1 hour, and then allowed to cool naturally.

[0010] Furthermore, the sodium salt is sodium bis(trifluoromethane)sulfonylimide (NaTFSI).

[0011] Furthermore, the thickness of the light-driven solid electrolyte membrane is 80-120 micrometers, preferably 100-105 micrometers.

[0012] Furthermore, the preparation method of the light-driven solid electrolyte membrane is as follows: polyethylene oxide, heterojunction filler, lignocellulose soft filler, and sodium salt are mixed in a solvent to obtain a membrane solution, which is then coated and dried to obtain the light-driven solid electrolyte membrane. Specifically, the operation can be carried out according to the following steps:

[0013] (1) Dissolve polyethylene oxide and sodium salt in acetonitrile at the same time and stir until homogeneous, without generating bubbles.

[0014] (2) After mixing the heterojunction filler and the lignocellulose soft filler in acetonitrile, add them to a solution of polyethylene oxide and sodium salt and stir thoroughly to obtain a uniformly dispersed viscous film liquid; preferably, stir at room temperature for 6-20 hours.

[0015] (3) The membrane solution is uniformly coated on a polytetrafluoroethylene plate and vacuum dried for a period of time to obtain a light-driven solid electrolyte membrane. Preferably, the vacuum drying temperature is 50-70℃ and the drying time is 24-60 hours.

[0016] This invention also discloses a photoelectrochemical storage cathode for a light-assisted solid-state sodium metal battery, which is prepared by sequentially and uniformly coating titanium dioxide and sodium vanadium phosphate onto the surface of an indium selenide thin film, followed by drying. Preferably, the drying temperature is 60°C and the drying time is 12 hours.

[0017] This invention further provides an integrated flexible light-assisted solid-state sodium metal battery, assembled from a positive electrode, a negative electrode, a solid electrolyte membrane, tabs, and a packaging film. The positive electrode material is the aforementioned photoelectrochemical storage positive electrode, the negative electrode is an ultrathin sodium metal foil, the solid electrolyte membrane is the aforementioned light-driven solid electrolyte membrane, and the packaging film is a transparent conductive film. Preferably, the packaging film is a light-transmitting indium selenide (ISS) film.

[0018] The integrated flexible light-assisted solid sodium metal battery can be prepared by stacking a transparent conductive film, a positive electrode (pre-connected with tabs), a solid electrolyte membrane, a negative electrode (pre-connected with tabs), and a transparent conductive film in sequence, and then encapsulating them with a battery sealing machine to obtain a transparent soft-pack battery.

[0019] The beneficial technical effects of this invention are reflected in the following aspects:

[0020] 1. Compared with traditional polyethylene oxide electrolytes, the light-driven solid electrolyte membrane provided by the present invention can generate a strong and stable photoelectric field by using heterojunction under light conditions without additional external pressure, thereby improving electrolyte performance, reducing interfacial impedance, effectively regulating the sodium salt dissociation and ion migration mechanism in the electrolyte, and effectively improving ionic conductivity and sodium ion transfer number.

[0021] 2. The light-driven solid electrolyte membrane provided by this invention, while maintaining high ionic conductivity, significantly improves mechanical properties by introducing lignocellulose, an environmentally friendly, high-mechanical-strength, sodium-compatible, and resource-rich biomass resource, thus facilitating the construction of flexible solid-state batteries.

[0022] 3. Based on the principle of energy level matching, the photoelectrochemical storage cathode provided by this invention can achieve high integration, improve the compatibility of the electrolyte / cathode interface, and significantly improve the sodium ion storage kinetics in the light-assisted mode, thereby achieving rapid sodium ion storage and excellent cycling performance.

[0023] 4. The novel flexible light-assisted solid sodium metal battery designed and assembled in this invention exhibits excellent long-term cycle stability. Attached Figure Description

[0024] Figure 1 This is a diagram illustrating the working mechanism of the light-driven solid electrolyte membrane of the present invention;

[0025] Figure 2 This is a schematic diagram of the energy level matching principle of the present invention;

[0026] Figure 3 This is a schematic diagram of the integrated flexible light-assisted solid-state sodium metal battery of the present invention;

[0027] Figure 4 This is the X-ray diffraction pattern of the heterojunction material prepared in Example 1 of this invention;

[0028] Figure 5 This is a scanning electron microscope image of the heterojunction material prepared in Example 1 of the present invention;

[0029] Figure 6 This is a transmission electron microscope (TEM) image of the heterojunction material prepared in Example 1 of this invention;

[0030] Figure 7 This is the X-ray diffraction pattern of the light-driven solid electrolyte membrane prepared in Example 1 of this invention;

[0031] Figure 8 This is a scanning electron microscope image of the light-driven solid electrolyte membrane prepared in Example 1 of the present invention;

[0032] Figure 9 Arenius diagrams of the light-driven solid electrolyte membrane prepared in Example 1 and the solid electrolyte membrane prepared in Comparative Example 1 of this invention.

[0033] Figure 10 This is an infrared thermal imaging temperature change diagram of the light-driven solid electrolyte membrane prepared in Example 1 of the present invention and the assembled "perforated steel sheet||solid electrolyte membrane||perforated steel sheet" structure under xenon lamp cold light source irradiation.

[0034] Figure 11 These are stress-strain test curves of the light-driven solid electrolyte membrane prepared in Example 1 of the present invention and the solid electrolyte membrane prepared in Comparative Example 1.

[0035] Figure 12 These are ion mobility diagrams of the light-driven solid electrolyte membrane prepared in Example 1 of the present invention and the solid electrolyte membrane prepared in Comparative Example 1.

[0036] Figure 13 This is a schematic diagram of an integrated flexible light-assisted solid-state sodium metal battery used to light up an LED display screen, prepared according to Embodiment 1 of the present invention.

[0037] Figure 14These are the cycle performance curves of the solid sodium metal batteries prepared in Example 1 and Comparative Example 1 of this invention under illumination and a current density of 0.2C.

[0038] Figure 15 This is the cycle performance curve of the solid sodium metal battery prepared in Example 1 of the present invention under illumination at a current density of 1C. Detailed Implementation

[0039] This invention provides an integrated flexible light-assisted solid-state sodium metal battery, assembled from a light-driven solid electrolyte membrane, a photoelectrochemical storage positive electrode, and a negative electrode. The light-driven solid electrolyte membrane is prepared by blending polyethylene oxide material, heterojunction filler, lignocellulose soft filler, and sodium salt to obtain a membrane solution, followed by uniform coating and drying. The heterojunction filler is a composite material of copper oxide and indium oxide. The mechanism of action of the light-driven solid electrolyte membrane in this invention is as follows: Figure 1 As shown, in traditional vinyl oxide solid polymer electrolytes, strong O-Na+ coordination significantly hinders sodium ion migration, resulting in a low sodium ion transfer number. This problem can be improved by optimizing the coordination environment and enhancing the dissociation of sodium salts. Specifically, when exposed to light, the photogenerated electric field of the photocatalytic heterojunction active filler weakens the O-Na+ coordination. + Coordination significantly accelerates the dissociation of sodium salts. After dissociation, the complexation of sodium ions with TFSI- must be suppressed to improve the availability of active sodium ions. Stable copper oxide has a narrow band gap. Indium oxide also has a relatively narrow band gap, and its unique In... 3+ The d10 electronic structure exhibits excellent visible light absorption, which is crucial for photocatalytic activity. Integrating copper oxide and indium oxide into the heterojunction structure can synergistically meet the requirements of light-driven modulation, thus providing a solid theoretical basis for the effective dissociation of sodium salts.

[0040] In this embodiment of the invention, the photoelectrochemical storage cathode designed based on the energy level matching principle is prepared by sequentially and uniformly coating titanium dioxide and sodium vanadium phosphate onto the surface of an indium selenide thin film, followed by drying. Figure 2 As shown, by utilizing the appropriate energy level combination between indium tin oxide, titanium dioxide, and sodium vanadium phosphate, effective transfer of photogenerated electrons and holes can be achieved.

[0041] This invention further provides an integrated flexible light-assisted solid-state sodium metal battery device, assembled from a positive electrode, a negative electrode, a solid electrolyte membrane, tabs, and a packaging film. The positive electrode material is a photoelectrochemical storage positive electrode, the negative electrode is an ultrathin sodium foil, the solid electrolyte membrane is the aforementioned light-driven solid electrolyte membrane, and the packaging film is a transparent conductive film. Preferably, a transparent indium tin oxide film is used as the packaging film to ensure light transmittance and flexibility. The structure of the integrated flexible light-assisted solid-state sodium metal battery device is as follows: Figure 3As shown.

[0042] The present invention will be further described in detail below through specific embodiments.

[0043] Example 1

[0044] This embodiment first prepares a light-driven solid electrolyte membrane, then prepares a photoelectrochemical storage cathode, and further assembles an integrated flexible light-assisted solid sodium metal battery device based on it. The specific operation steps are as follows:

[0045] 1. 0.080 mmol indium nitrate hexahydrate, 0.034 mmol copper nitrate trihydrate, 0.512 mmol 4,5-imidazolium dicarboxylic acid, and 1.692 mmol benzimidazole were dissolved in 16 mL of dimethylformamide. The mixture was ultrasonically stirred for 10 minutes to ensure complete dissolution. Next, the reaction mixture was heated to 120 °C and maintained with continuous stirring for 4 hours. After the reaction was complete, the product was collected by centrifugation, washed three times with distilled water and ethanol to remove any residual reactants, and dried at 60 °C for 24 hours. Then, the dried sample was ground and heat-treated at 500 °C at a heating rate of 2 °C per minute under an argon atmosphere and held at that temperature for 1 hour to synthesize the heterojunction filler copper oxide / indium oxide. The X-ray diffraction pattern of the resulting heterojunction is shown below. Figure 4 As shown, the scanning electron microscope image is as follows: Figure 5 As shown, the transmission electron microscope image is as follows: Figure 6 As shown.

[0046] 2. Sodium bis(trifluoromethane)sulfonylimide (NaTFSI) and polyethylene oxide were added to anhydrous acetonitrile, with the molar ratio of ethylene oxide [EO] to [Na] fixed at 18:1. The mixture was then stirred thoroughly until completely dissolved and no bubbles were generated. Copper oxide / indium oxide was dispersed in the above solution at a mass fraction of 5% in the electrolyte membrane and lignocellulose at a mass fraction of 2% in the electrolyte membrane. The mixture was then stirred thoroughly until completely dissolved and the bubbles disappeared, resulting in a homogeneous membrane solution.

[0047] 3. The above-mentioned membrane solution was coated onto a polytetrafluoroethylene plate and stretched using a film stretcher. Subsequently, it was vacuum dried at 60°C for 48 hours to obtain a light-driven tunable heterojunction solid electrolyte membrane (thickness ~100 micrometers). Its X-ray diffraction pattern is shown below. Figure 7 As shown, the scanning electron microscope image is as follows: Figure 8 As shown.

[0048] 4. Dissolve 0.3 g of titanium dioxide powder in 3 mL of N-methylpyrrolidone and stir for 6 hours. Coat the mixture uniformly onto the surface of an indium selenide (ISS) film and dry at 60 °C for 12 hours. Then, mix sodium vanadium phosphate, conductive carbon black, and polyvinylidene fluoride binder in an N-methylpyrrolidone solution at a mass ratio of 8:1:1 to form a uniform slurry. Coat this slurry uniformly onto the ISS film surface using a 200 μm thin film stretching apparatus and vacuum dry overnight at 60 °C to obtain the photoelectrochemical storage cathode.

[0049] 5. Cut the purchased indium selenide film with a thickness of 0.125 mm and a sheet resistance of 5 ohms into 5.5 cm × 3.5 cm pieces, then clean them ultrasonically with detergent, deionized water, ethanol and acetone in sequence, and then vacuum dry them.

[0050] 6. In an argon-filled glove box, ultrathin sodium foil, photoexcitation-controlled heterojunction solid electrolyte membrane, and photoelectrochemical storage cathode (pre-drilled) are stacked in sequence, and then encapsulated on a battery packaging machine with indium tin oxide film. The integrated flexible photo-assisted solid sodium metal battery is then assembled.

[0051] Comparative Example 1

[0052] Polyethylene oxide and NaTFSI were added to anhydrous acetonitrile, with the ratio of ethylene oxide [EO] to [Na] fixed at 18:1. The mixture was stirred thoroughly until completely dissolved and no bubbles were generated. The mixture was then coated onto a polytetrafluoroethylene (PTFE) plate and stretched using a film stretcher. It was subsequently dried at 60°C for 48 hours to obtain a polyethylene oxide solid electrolyte membrane (approximately 85 micrometers thick).

[0053] Using the same positive electrode, negative electrode, and indium selenide thin film as in Example 1, the electrolyte membrane obtained in this example was assembled into a solid sodium metal battery according to the same method as in Example 1.

[0054] The solid electrolyte membranes obtained in the above embodiments and comparative examples were subjected to the following performance tests:

[0055] 1. Ionic conductivity: Assemble a “perforated steel sheet || solid electrolyte membrane || perforated steel sheet” structure, encapsulate it with a perforated battery case (CR2032, perforation diameter 5 mm, KELUD Co., Ltd.), and simulate light irradiation of the solid electrolyte membrane through the perforation using a xenon lamp cold light source. Test the bulk impedance R at different temperatures, and calculate the ionic conductivity σ at different temperatures according to the formula σ=l / RS, where l is the thickness of the film, R is the bulk impedance value, and S is the area of ​​the film.

[0056] Test results as follows Figure 9As shown: The solid electrolyte membrane prepared in Comparative Example 1 is not responsive to light, and its ionic conductivity at 40°C is 0.04 mS / cm; the solid electrolyte membrane prepared in Example 1 has an ionic conductivity of 0.067 mS / cm at 40°C under no light conditions and an ionic conductivity of 0.101 mS / cm at 40°C under light conditions.

[0057] To eliminate the influence of temperature, the light-driven solid electrolyte membrane prepared in Example 1 and its assembled "perforated steel sheet || solid electrolyte membrane || perforated steel sheet" structure were irradiated with a xenon lamp cold light source, and the temperature was monitored in real time using an infrared thermal imaging camera. Figure 10 As shown, this confirms that the light source does not affect the battery temperature.

[0058] 2. Stress-strain test: The electrolyte membrane is prepared as a 3cm×6cm sample. A tensile tester is used to apply a gradually increasing tensile load until the sample is deformed and eventually fails. The maximum tensile stress required for the sample to fail is the stress yield strength.

[0059] Test results as follows Figure 11 As shown, comparing Example 1 and Comparative Example 1, it can be seen that the solid electrolyte membrane provided by the present invention, by adding lignocellulose and heterojunction filler to polyethylene oxide, has a stress strength 1.65 times that of Comparative Example 1 (the stress yield strength of the solid electrolyte membrane obtained in Example 1 is 6.37 MPa, and the stress yield strength of the solid electrolyte membrane obtained in Comparative Example 1 is 3.85 MPa), indicating that the solid electrolyte membrane provided by the present invention has good mechanical properties.

[0060] 3. Ion Transport Number Detection: A symmetrical cell with a "pore-filled sodium || solid electrolyte membrane || pore-filled sodium" structure was assembled and clamped on both sides with perforated steel sheets. It was then encapsulated using a perforated battery case (CR2032, 5 mm perforation diameter, KELUD Co., Ltd.). The perforations on the sodium sheet, steel sheet, and battery case were aligned to ensure that the light source could illuminate the solid electrolyte membrane. Testing was conducted on an electrochemical workstation, with the solid electrolyte membrane illuminated from the perforations using a xenon lamp cold light source. Figure 12 As shown, the results indicate that the solid electrolyte membrane obtained in Example 1 has an ion transport number of 0.42 at 40°C under no light conditions and an ion transport number of 0.49 at 40°C under light conditions; the solid electrolyte membrane obtained in Comparative Example 1 is not responsive to light and has an ion transport number of 0.17 at 40°C.

[0061] 4. Cycle count test: The integrated flexible light-assisted solid sodium metal battery assembled in the above embodiment and comparative example is placed on the Xinwei test software. After setting the charge and discharge rate, cutoff voltage and other test conditions, the test is started. At the same time, the solid electrolyte membrane is irradiated from the perforated position of the photoelectrochemical storage positive electrode by a xenon lamp cold light source or natural light, and the cycle is waited for.

[0062] Under the illumination of a xenon lamp's cold light source, such as Figure 13 As shown, Example 1 successfully powered an LED using a pouch cell assembled with a photoelectrochemical storage positive electrode, while maintaining stable performance under bending conditions.

[0063] The electrochemical cycling performance curves of the solid sodium metal batteries prepared in Example 1 and Comparative Example 1 under illumination and a current density of 0.2C are shown below. Figure 14 As shown, at a current density of 0.2C, the pouch cell assembled in Example 1 had an initial discharge capacity of 122.5 mAh / g, and after 125 cycles, the capacity retention rate was 98.3%, with an energy storage efficiency as high as 98.2%. In contrast, the pouch cell assembled in Comparative Example 1 had an initial discharge capacity of 101.6 mAh / g at a current density of 0.2C, exhibiting poor cycle stability.

[0064] The cycling performance curve of the solid sodium metal battery prepared in Example 1 at a 1C current density under illumination is shown in the figure below. Figure 15 As shown. At a current density of 1C, the pouch cell assembled in Example 1 had an initial discharge capacity of 132 mAh / g, a capacity retention of 89.1% after 300 cycles, and an energy storage efficiency of up to 96.8%.

[0065] In summary, the integrated flexible light-assisted solid-state sodium metal battery benefits from the modification of the heterojunction solid electrolyte membrane and the photoelectrochemical storage cathode through photoexcitation modulation, achieving high ionic conductivity, excellent electrochemical stability, mechanical strength, and dendritic resistance. The rational design of the energy-level matched coupled photoelectrochemical storage cathode effectively utilizes visible light and increases the strong compatibility between the electrolyte and the cathode, enabling the integrated flexible light-assisted solid-state sodium metal battery to achieve long-term cycle stability.

[0066] Those skilled in the art will readily understand that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A light-driven solid-state electrolyte membrane for a light-assisted solid- state sodium metal battery, characterized by: The light-driven solid-state electrolyte membrane is prepared from polyethylene oxide, a heterojunction filler, a lignocellulosic soft filler and a sodium salt; the content of the heterojunction filler accounts for 1-20% of the total mass of the solid-state electrolyte membrane, and the content of the lignocellulosic soft filler accounts for 0.5-3% of the total mass of the solid-state electrolyte membrane. The heterojunction filler is a composite material of copper oxide and indium oxide, and the preparation method of the heterojunction filler is as follows: indium nitrate hexahydrate, copper nitrate trihydrate, 4,5-imidazole dicarboxylic acid and benzimidazole are added to dimethylformamide in a molar ratio of 0.08:0.034:0.512:1.5-2.0 and ultrasonically stirred until dissolved; the obtained reaction mixture is heated to 90-120℃ and kept under continuous stirring for 2-10 hours, then centrifuged, dried, and then annealed at 400-600℃ in a tube furnace filled with argon atmosphere to obtain the heterojunction filler.

2. The optically driven solid-state electrolyte membrane of claim 1, wherein, The thickness of the light-driven solid-state electrolyte membrane is 80-120 microns.

3. A method of preparing the optically driven solid-state electrolyte film according to claim 1 or 2, characterized by: The polyethylene oxide, the heterojunction filler, the lignocellulosic soft filler and the sodium salt are blended in a solvent to obtain a membrane liquid, and then the light-driven solid-state electrolyte membrane is prepared by coating and drying.

4. An integrated flexible light-assisted solid-state sodium metal battery, characterized by: The integrated flexible light-assisted solid-state sodium metal battery comprises the light-driven solid-state electrolyte membrane of claim 1 or 2, and further comprises a photoelectrochemical storage anode; the photoelectrochemical storage anode is prepared by sequentially and uniformly coating titanium dioxide and sodium vanadium phosphate on the surface of an indium selenide oxide film, and then drying.

5. The integrated flexible photo-assisted solid-sodium metal battery of claim 4, wherein: The integrated flexible light-assisted solid-state sodium metal battery is assembled from the photoelectrochemical storage anode, a sodium metal negative electrode, the light-driven solid-state electrolyte membrane, a tab and a packaging film.

6. The integrated flexible photo-assisted solid-sodium metal battery of claim 5, wherein: The packaging film is a transparent conductive film.

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