An illumination self-charging aqueous zinc ion battery device and a preparation method thereof

Abstract

The present application relates to the structural design of aqueous zinc-ion battery, in particular to a kind of light self-charging aqueous zinc-ion battery device and preparation method thereof.The preparation method comprises the following steps: S1, preparation V2O3@TiO2 Hollow nanospheres;S2, preparation positive plate;S3, preparation aluminum plastic film packaging material;S4, with glass fiber separator as separator, zinc foil as negative plate, positive plate, glass fiber separator and negative plate are stacked in sequence after being loaded into aluminum plastic film packaging material, electrolyte is injected, and packaging treatment is carried out, to obtain light self-charging aqueous zinc-ion battery.The light self-charging aqueous zinc-ion battery of the present application adopts the core-shell structure positive electrode material of V2O3@TiO2 Hollow nanospheres heterojunction, has more optimal photoelectric conversion efficiency, and the battery of the present application can be self-charged by providing light, and can be light self-charged to 1.116 V, significantly higher than traditional aqueous zinc-ion battery.

Description

Technical Field

[0001] This invention relates to the structural design of aqueous zinc-ion batteries, and in particular to a light-induced self-charging aqueous zinc-ion battery device and its preparation method. Background Technology

[0002] With the rapid development of science and technology, new energy storage devices that combine high safety, low cost, long life and high energy density have received widespread attention and in-depth research, and are rapidly being integrated into people's daily lives, showing great application prospects in portable electronic devices, large-scale energy storage systems, electric vehicles and other fields.

[0003] Aqueous zinc-ion batteries, based on aqueous electrolytes, possess significant advantages such as intrinsic safety, environmental friendliness, high ionic conductivity, abundant zinc resources, and low cost, making them a crucial candidate system for next-generation large-scale energy storage and portable devices, attracting considerable attention from both academia and industry. However, traditional aqueous zinc-ion batteries still face challenges such as poor conductivity of cathode materials, slow ion transport rates, insufficient structural stability, and the inability to effectively utilize clean energy to enhance electrochemical performance. These limitations hinder their actual capacity and overall performance from meeting the growing application demands, thus restricting their further promotion and application. Therefore, developing high-performance aqueous zinc-ion batteries with high capacity, excellent cycle stability, and the ability to achieve clean energy-assisted efficiency enhancement is of great significance for promoting the development of future energy storage technologies and intelligent electronic devices.

[0004] To improve the electrochemical performance of aqueous zinc-ion batteries, current research largely focuses on the design and modification of electrode materials. This is achieved by controlling material morphology and structure, constructing conductive networks, and modifying interfaces to enhance ion diffusion rates and electronic conductivity, thereby improving battery specific capacity and cycle stability. While techniques such as combining highly conductive materials and optimizing electrolyte systems can improve the electrochemical performance of zinc-ion batteries, some strategies suffer from complex fabrication processes, high production costs, and difficulties in large-scale application. Furthermore, they fail to achieve efficient utilization of clean energy, making it difficult to meet the requirements of practical production and application.

[0005] Solar energy, as a widely available, clean, renewable, and pollution-free green energy source, is of great value for achieving sustainable energy storage through its efficient utilization. Therefore, constructing an aqueous zinc-ion battery system with photoresponsive characteristics, leveraging light to modulate the electronic structure and ion transport behavior of the electrodes, and improving the reaction kinetics during charging and discharging to achieve photo-assisted self-charging and capacity enhancement, has become a highly promising development direction. By introducing the photo-assisted effect, the capacity output, charge-discharge efficiency, and cycle stability of zinc-ion batteries can be significantly improved under illumination, thereby enhancing the overall electrochemical performance of the battery. Therefore, there is an urgent need to develop a photo-assisted self-charging aqueous zinc-ion battery technology that can efficiently utilize solar energy and possesses excellent photoelectric response and electrochemical performance, providing a new technological path for high-performance, green, and sustainable new energy storage devices. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a light-illuminated self-charging aqueous zinc-ion battery device and its preparation method, which can effectively improve the current density during charging and discharging under illumination, increase the capacity of the aqueous zinc-ion battery, and improve cycle stability.

[0007] This invention provides a method for preparing a light-induced self-charging aqueous zinc-ion battery device, comprising the following steps: S1. VO2 hollow nanospheres were prepared by hydrothermal method. TiO2 was coated on the surface of the VO2 hollow nanospheres by solution method and then calcined to obtain V2O3@TiO2 hollow nanospheres. S2. The V2O3@TiO2 hollow nanospheres, carbon nanotubes and polyvinylidene fluoride obtained in step S1 are mixed in proportion, dissolved evenly in solvent and then subjected to ultrasonic treatment; then, the slurry is coated onto graphite foil, and the graphite foil loaded with the material is dried to obtain the positive electrode sheet. S3. A rectangular light-transmitting hole is made in the positive electrode aluminum-plastic film shell, and the light-transmitting hole is covered with PET film, cured and sealed to form a transparent light-transmitting window, thus obtaining the aluminum-plastic film encapsulation material; S4. Using a glass fiber separator as the separator and zinc foil as the negative electrode, the positive electrode, glass fiber separator and negative electrode are stacked in sequence and then placed into an aluminum-plastic film encapsulation material. Electrolyte is injected and encapsulated to obtain a light-illuminated self-charging aqueous zinc-ion battery.

[0008] Furthermore, in step S1, the preparation method of V2O3@TiO2 hollow nanospheres is as follows: S11. Vanadium oxalate precursor powder is uniformly dissolved in the mixed solution, and then subjected to heating, cooling, centrifugation, washing and drying processes to obtain VO2 hollow nanospheres. S12. First, the prepared VO2 hollow nanospheres were ultrasonically dispersed in anhydrous ethanol, and then an aqueous surfactant solution was added and stirred vigorously to obtain a VO2 suspension. Tetrabutyl titanate was uniformly dissolved in the ethanol solution to obtain the reaction stock solution. The VO2 suspension was heated in a water bath, and then the reaction stock solution was slowly added dropwise to the VO2 suspension. After vigorous stirring, the mixture was subjected to aging, centrifugation, drying and calcination treatments in sequence to obtain V2O3@TiO2 hollow nanospheres.

[0009] Further, in step S11, the mixed solution is prepared by methanol and water in a volume ratio of 4:1, and the solid-liquid ratio of vanadium oxalate precursor powder and mixed solution is 5:6.

[0010] Further, in step S12, the surfactant aqueous solution is a polyethylene glycol tert-octylphenyl ether aqueous solution; the solid-liquid ratio of VO2 hollow nanospheres to anhydrous ethanol is 3:5; the volume ratio of tetrabutyl titanate to anhydrous ethanol is 0.3:5; and the volume ratio of the reaction stock solution to the VO2 suspension is 1:1. Further, in step S12, the calcination conditions are: 10℃ min -1 The temperature was increased to 400℃ and calcined for 15 minutes.

[0011] Further, in step S2, the mass ratio of V2O3@TiO2 hollow nanospheres: carbon nanotubes: polyvinylidene fluoride is 7:2:1, and the solvent is N-methylpyrrolidone.

[0012] Furthermore, in step S3, an ITO layer is coated on the PET film, and before curing and sealing, the ITO layer of the PET film is positioned facing the inside of the positive electrode aluminum-plastic film shell; The curing and sealing process involves sequentially applying UV adhesive and UV laser curing.

[0013] Furthermore, in step S4, a 3M zinc trifluoromethanesulfonate solution is used as the battery electrolyte.

[0014] A light-induced self-charging aqueous zinc-ion battery device is prepared using the above-described method.

[0015] The beneficial effects of this invention are as follows: (1) The photo-rechargeable aqueous zinc-ion battery prepared in this invention possesses high-efficiency photoresponse and self-charging capabilities, and can be directly charged without an external power source using sunlight: when the light-transmitting surface faces the sun, the open-circuit voltage steadily increases with the duration of illumination, rising from an initial voltage of 0.649V to 1.111V after 5 hours of illumination; while the voltage remains almost unchanged when the opaque surface faces the sun, directly demonstrating the photo-rechargeable capability. Simultaneously, under 9 hours of continuous xenon lamp illumination, the voltage can stably increase from 0.88V to 1.01V, exhibiting reliable photo-charging dynamics. At 10 mAg...- ¹Under current density and illumination, the discharge capacity reaches 350 mAh g. - ¹, the improvement of 139.7% compared to the dark state is significantly higher than that of traditional aqueous zinc-ion batteries, proving that light can enhance electrode reactivity and ion transport efficiency, and greatly improve the energy density of the device; (2) The light-assisted self-charging aqueous zinc-ion battery prepared by this invention possesses both a fast and stable photocurrent response and optimized interface kinetics. Under periodic light-dark alternation testing, it can generate a stable negative photocurrent with a peak value of approximately -80 μA, and the signal shows no significant attenuation after multiple cycles, providing a solid kinetic foundation for self-charging and capacity improvement. Electrochemical impedance spectroscopy analysis shows that light irradiation can effectively reduce the interface charge transfer resistance and ion diffusion resistance, revealing the core advantages of light-assisted charging and discharging from a mechanistic perspective. In addition, this invention uses an aqueous electrolyte, completely avoiding the safety hazards of traditional organic electrolytes. Combined with the self-charging characteristics of solar energy, it provides a green, sustainable, and efficient energy storage solution for portable electronic devices, outdoor emergency energy storage, and other scenarios, which is in line with the development direction of low-carbon energy.

[0016] (3) The present invention adopts a modular structure design and scalable manufacturing process, which can realize the flexible expansion of battery capacity from the mAh level to the ampere-hour level. At the same time, the modular design and manufacturing process have good versatility, compatibility and reproducibility. The process steps are simple and controllable, without the need for complex equipment modification or large-scale parameter adjustment. It can be well adapted to the needs of industrial continuous production and large-scale manufacturing, and has high engineering application value and industrialization prospects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the front structure of the light-induced self-charging aqueous zinc-ion battery prepared in Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the structure of the light-induced self-charging aqueous zinc-ion battery prepared in Example 1 of the present invention; Figure 3 The photoresponse current curve of the self-charging aqueous zinc-ion battery prepared in Example 2 of the present invention under periodic illumination conditions; Figure 4 The image shows the EIS impedance curves of the self-charging aqueous zinc-ion battery prepared in Example 2 of this invention under both light and dark conditions.

[0018] Figure 5 The image shows the GCD charge-discharge curves of the self-charging aqueous zinc-ion battery prepared in Example 2 of this invention under both light and dark conditions.

[0019] Figure 6 This is a graph showing the self-charging curves of the aqueous zinc-ion battery prepared in Example 2 of the present invention under both xenon lamp illumination and non-illumination conditions.

[0020] Figure 7 This is an example of a self-charging aqueous zinc-ion battery prepared according to Embodiment 2 of the present invention under sunlight, with the opaque side facing the sun.

[0021] Figure 8 This is an example of a self-charging aqueous zinc-ion battery prepared according to Embodiment 2 of the present invention, with the light-transmitting side facing the sun.

[0022] Figure 1 In the middle: 1. Shell; 2. Negative electrode tab; 3. Positive electrode tab; 4. Negative electrode sheet; 5. Electrolyte; 6. PET film coated with ITO; 7. Positive electrode sheet; 8. Glass fiber diaphragm. Detailed Implementation

[0023] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the technical solutions of this invention will be further described in detail below with reference to specific embodiments and accompanying drawings. Where specific test methods, instruments, and experimental conditions are not explicitly indicated in the embodiments, they are all performed in accordance with existing technologies known in the art, technical specifications recorded in relevant literature, or instrument / reagent product instructions; where the manufacturers of reagents, consumables, and instruments are not specified, they are all standard products that can be obtained through conventional commercial channels.

[0024] The first aspect of this invention is to protect a method for preparing a light-induced self-charging aqueous zinc-ion battery device, comprising the following steps: S1. VO2 hollow nanospheres were prepared by hydrothermal method, and TiO2 was coated on their surface by solution method. V2O3@TiO2 hollow nanospheres were obtained by calcination and reduction in a tube furnace. This is an active powder material.

[0025] Specifically, the hydrothermal method for preparing the VO2 hollow nanospheres is as follows: Vanadium oxalate precursor powder is added to a mixed solution of methanol and water; after magnetic stirring for 10 minutes, the resulting light green translucent solution is transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene, and heated in an electrically heated air-circulating oven at 200°C for 24 hours; after natural cooling, the resulting black product is collected by centrifugation, washed repeatedly with deionized water and ethanol, and dried overnight at 60°C to finally obtain the VO2 hollow nanosphere sample. In this invention, the mixed solution is prepared by methanol and water at a volume ratio of 4:1, and the solid-liquid ratio of the vanadium oxalate precursor powder to the mixed solution is 5:6. The method for coating TiO2 onto the surface of VO2 hollow nanospheres using a solution method is as follows: First, the prepared VO2 hollow nanospheres are ultrasonically dispersed in anhydrous ethanol for 5 min. Then, a Triton X-100 surfactant aqueous solution (concentration 0.1 M) is added to the suspension and stirred vigorously for 1 h. Tetrabutyl titanate (TBOT) is dissolved in the ethanol solution and stirred for 1 h to prepare the reaction stock solution. The VO2 suspension is heated in an 80℃ water bath, and then the reaction stock solution is slowly added dropwise to the VO2 suspension and stirred vigorously for 30 min. Then, the suspension mixture is aged for 4 h. The VO2 hollow nanospheres coated with TiO2 are collected by centrifugation and dried in a vacuum oven for 12 h. Finally, they are placed in a vacuum tube furnace (purged with nitrogen 4 times and then evacuated) and heated at 10℃ for 1 min. -1 The temperature was increased to 400℃ and calcined for 15 min to obtain V2O3@TiO2 hollow nanospheres with TiO2 coating on the surface; wherein, the surfactant aqueous solution was polyethylene glycol tert-octylphenyl ether aqueous solution; the solid-liquid ratio of VO2 hollow nanospheres to anhydrous ethanol was 30:50; the volume ratio of tetrabutyl titanate to anhydrous ethanol was 0.3:5; and the volume ratio of the reaction stock solution to the VO2 suspension was 1:1.

[0026] S2. Using graphite foil as the positive electrode substrate, the prepared V2O3@TiO2 hollow nanospheres, carbon nanotubes (CNTs), and polyvinylidene fluoride (PVDF5130) were mixed in a mass ratio of 7:2:1. N-methylpyrrolidone (NMP) was added, and the mixture was ultrasonically treated for 2 hours. The ultrasonic treatment was paused every 20 minutes, and the centrifuge tube was shaken to obtain a slurry. The slurry was then coated onto the graphite foil. The graphite foil used here needed to be pre-cleaned with deionized water and ethanol, and then cleaned with a plasma cleaner for 5 minutes to improve its hydrophilicity. The graphite foil loaded with the slurry was then transferred to a vacuum oven and dried at 60°C for 12 hours to obtain the positive electrode sheet.

[0027] S3. A rectangular light-transmitting hole is opened in the positive electrode aluminum-plastic film shell, and the light-transmitting hole is covered with a PET film coated with indium tin oxide (ITO), with the ITO coating side of the PET film facing inward. UV adhesive is applied at the connection between the PET film and the aluminum-plastic film shell, and then sealed by UV laser curing to form a transparent light-transmitting window, thus obtaining the aluminum-plastic film encapsulation material. S4. A glass fiber separator is used as the battery separator, and the preset width of the battery separator is greater than the preset width of the positive electrode and the negative electrode. Zinc foil is used as the negative electrode and 3M zinc trifluoromethanesulfonate solution is used as the battery electrolyte. The positive electrode, glass fiber separator and negative electrode are stacked in sequence and then placed into the aluminum-plastic film encapsulation material processed in step S3. An appropriate amount of electrolyte is injected and the battery is encapsulated to obtain a light-illuminated self-charging aqueous zinc-ion battery.

[0028] In this invention, the glass fiber diaphragm is 8*8cm in size, the negative electrode is 7*7cm in size, the positive electrode is 7*7cm in size, and the amount of 3M zinc trifluoromethanesulfonate solution used is 5mL.

[0029] In this invention, the V2O3@TiO2 hollow nanosphere cathode material, with its unique heterostructure and hollow morphology, exhibits excellent light-harvesting and carrier separation characteristics, providing a core material foundation for constructing a self-charging aqueous zinc-ion battery that can utilize natural sunlight. Specifically, the narrow bandgap V2O3 effectively absorbs visible light and generates photogenerated carriers, while the wide bandgap TiO2 acts as an electron transport layer, promoting the effective separation of photogenerated electron-hole pairs and suppressing their recombination. The hollow structure further enhances light absorption efficiency by increasing the light scattering path and extending the residence time of photons within the material, while simultaneously providing ample channels for ion diffusion.

[0030] The second point to be protected in this invention is the light-induced self-charging aqueous zinc-ion battery obtained by the above-described preparation method. For example... Figures 1-2 As shown, specifically, the photo-rechargeable aqueous zinc-ion battery of the present invention includes a casing 1, a negative electrode 4, an electrolyte 5, a positive electrode 7, and a glass fiber separator 8. The casing 1 is the aluminum-plastic film encapsulation material obtained in step S3. The electrolyte within it possesses excellent barrier properties, effectively isolating air and moisture. Furthermore, the three sides of the casing 1, except for the encapsulated side, are sealed and compacted, effectively preventing electrolyte leakage during subsequent use and avoiding impact on the normal operation of the photo-rechargeable aqueous zinc-ion battery and its supporting equipment. Simultaneously, a rectangular light-transmitting hole is opened in the positive electrode aluminum-plastic film casing, covered with an ITO-coated PET film, and sealed with UV adhesive and UV laser curing to form a transparent light-transmitting window, enabling light incidence and light-assisted control. Based on the above material properties, we designed a light-transmitting soft-pack battery to achieve direct utilization of natural sunlight. This battery adopts a transparent encapsulation structure to ensure that sunlight can penetrate and irradiate the positive electrode material.

[0031] The upper end of the casing 1 is uniformly sealed by a plastic sealing machine. In actual operation, this can effectively prevent external gas from entering the interior of the aqueous zinc-ion soft-pack battery, avoid oxidation of the aqueous electrolyte upon contact with air, and ensure the stability of the electrochemical performance of the aqueous zinc-ion soft-pack battery. Positive electrode tab 2 and negative electrode tab 1 are connected to the same side of the upper sealing port. Positive electrode tab 2 is laser-welded to positive electrode plate 7, and negative electrode plate 4 is laser-welded to negative electrode tab 1.

[0032] <Example 1> A photoluminescent self-charging aqueous zinc-ion battery device includes a housing 1, a negative electrode 4, an electrolyte 5, a positive electrode 7, and a glass fiber separator 8. The housing 1 has a three-layer stacked structure, and the stacking order from left to right is: negative electrode 4 → glass fiber separator 8 → positive electrode 7 → glass fiber separator 8 → negative electrode 4 → glass fiber separator 8 → positive electrode 7 → glass fiber separator 8 → negative electrode 4 → glass fiber separator 8 → positive electrode, forming three complete stacked units. The positive electrode 7 and the positive electrode tab 3, and the negative electrode 4 and the negative electrode tab 1 are all connected by laser welding, which is firm and tight, effectively preventing the tabs from falling off and ensuring the stability of current conduction. The glass fiber separator 8 is set between the positive electrode 7 and the negative electrode 4 and each stacked unit to prevent short circuits that could cause safety accidents, while ensuring the smooth migration of zinc ions and ensuring the normal charging and discharging of the photoluminescent self-charging aqueous zinc-ion battery.

[0033] <Example 2> A method for fabricating a light-induced self-charging aqueous zinc-ion battery device includes the following steps: S1. VO2 hollow nanospheres were prepared by hydrothermal method, and TiO2 was coated on their surface by solution method. V2O3@TiO2 hollow nanospheres were obtained by calcination and reduction in a tube furnace.

[0034] Specifically, the hydrothermal method for preparing the VO2 hollow nanospheres is as follows: 50 mg of vanadium oxalate precursor powder is added to a 60 mL mixture of methanol and water (wherein the volume ratio of methanol to water is 4:1); after magnetic stirring for 10 minutes, the resulting light green translucent solution is transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and heated in an electrically heated air circulating oven at 200°C for 24 h. After natural cooling, the resulting black product is collected by centrifugation, washed multiple times with deionized water and ethanol, and dried overnight at 60°C to finally obtain the VO2 hollow nanosphere sample. The method for coating TiO2 onto the surface of VO2 hollow nanospheres using a solution method is as follows: 30.0 mg of prepared VO2 nanopowder was first ultrasonically dispersed in 50 ml of anhydrous ethanol for 5 min. Then, 800 μL of a 0.1 M Triton X-100 surfactant aqueous solution was added to the suspension, and the mixture was stirred vigorously for 1 h to obtain a VO2 suspension. 300 μL of TBOT was dissolved in 50 ml of ethanol solution and stirred for 1 h to prepare a reaction stock solution. The VO2 suspension was heated in an 80 °C water bath, and the reaction stock solution was slowly added dropwise to the VO2 suspension. After vigorous stirring for 30 min, the mixture was aged for 4 h. After centrifugation, drying, and calcination, V2O3 hollow nanosphere samples coated with TiO2 were obtained. Drying was performed in a vacuum oven for 12 h; calcination was performed in a vacuum tube furnace at 10 °C for 1 min. -1 The temperature was increased to 400℃ and calcined for 15 minutes.

[0035] S2. In preparing the working electrode, firstly, V2O3@TiO2 hollow nanospheres, carbon nanotubes and polyvinylidene fluoride were mixed in a ratio of 7:2:1, and then 8 mL of N-methylpyrrolidone was added. After ultrasonic treatment for 2 h, the slurry was coated onto a graphite foil. Then, the graphite foil loaded with the material was transferred to a vacuum oven and dried at 60 °C for 12 h to obtain the positive electrode sheet. S3. A rectangular light-transmitting hole is opened in the positive electrode aluminum-plastic film shell, and the light-transmitting hole is covered with an ITO-coated PET film with the ITO coating side facing inward. UV tape is applied at the connection between the PET film and the aluminum-plastic film shell, and then sealed by UV laser curing to form a transparent light-transmitting window, thus obtaining the aluminum-plastic film encapsulation material. S4. A glass fiber separator is used as the battery separator, commercial zinc foil is used as the negative electrode, and 3M zinc trifluoromethanesulfonate solution is used as the battery electrolyte. The positive electrode, glass fiber separator, and negative electrode are stacked in sequence and then placed into the aluminum-plastic film encapsulation material processed in step S3. An appropriate amount of electrolyte is injected and the battery is encapsulated to obtain a light-illuminated self-charging aqueous zinc-ion battery. The glass fiber separator has a size of 8*8cm, the negative electrode has a size of 7*7cm, the positive electrode has a size of 7*7cm, and the amount of 3M zinc trifluoromethanesulfonate solution used is 5mL.

[0036] The V2O3@TiO2 hollow nanospheres prepared in this embodiment were used to prepare positive electrode sheets, which were then cut into 12 mm diameter circular electrodes. These were used to assemble CR2032 coin cells, and the transient photocurrent of the materials was tested using the coin cells. The results are as follows: Figure 3 As shown. The assembly method of the CR2032 button cell is as follows: A CR2032 button cell cathode shell structure is adopted, and an 8 mm diameter hole is made in the center of the shell. A layer of UV tape is coated on the hole. To form a transparent window, a PET film (ITO coating side of the PET film facing inward, 12 mm) prepared in this embodiment is covered over the hole. Then, UV laser treatment is used to cure the PET film and firmly seal it to the shell. A zinc foil negative electrode (16 mm diameter, 0.05 mm thickness), a V2O3@TiO2 hollow nanosphere positive electrode sheet, and a glass microfiber separator (Whatman GF / DA6, 16 mm) are stacked and placed inside the CR2032 button cell cathode shell. Finally, 120 μL of 3M zinc trifluoromethanesulfonate electrolyte is added to the CR2032 button cell cathode shell to obtain the assembled CR2032 button cell. Figure 3It is evident that under periodic light-dark switching conditions, the response current of the V2O3@TiO2 hollow nanosphere material exhibits rapid and reversible periodic spikes. Under illumination, photogenerated electrons are rapidly excited and participate in the electrode reaction, leading to a significant increase in current; under dark conditions, the current rapidly decreases, demonstrating a good photo-switching effect. This proves that the V2O3@TiO2 hollow nanospheres are a highly efficient photoresponsive electrode material capable of effectively converting light energy into electrochemical energy, further confirming the material's photoresponsiveness.

[0037] The EIS impedance curves of the self-charging aqueous zinc-ion battery prepared in this embodiment under both illumination and non-illuminated conditions are obtained, and the results are as follows: Figure 4 As shown, compared to the dark curve, the diameter of the high-frequency semicircle under light conditions is significantly reduced, indicating that the generation of photogenerated carriers effectively reduces the charge transfer resistance at the electrode / electrolyte interface and enhances the electrochemical reaction kinetics. Simultaneously, the additional semicircle and gentler low-frequency slope in the mid-to-low frequency region suggest that light illumination also optimizes the insertion / extraction process of zinc ions at the electrode / electrolyte interface, reducing ion diffusion impedance. This result is highly consistent with the phenomenon of a steady increase in voltage and a significant increase in discharge capacity over time in the light-assisted self-charging experiment, directly confirming that light energy can optimize the battery interface impedance behavior by exciting photogenerated carriers, providing efficient kinetic support for the self-charging process, and revealing the core mechanism of light-assisted charging.

[0038] The constant current charge-discharge (GCD) test results of the light-induced self-charging aqueous zinc-ion battery prepared in this embodiment are as follows. Figure 5 As shown. By Figure 5 It can be seen that the performance enhancement effect of light on the self-charging aqueous zinc-ion battery under light exposure was directly verified in the constant current charge-discharge (GCD) test. Under no-light conditions, the specific capacity of the self-charging aqueous zinc-ion battery under light exposure was only 146 mAh g⁻¹. - ¹, The charge / discharge platform is relatively short; however, under illumination, the specific capacity is significantly increased to 350 mAh g. - ¹ The discharge plateau is significantly extended, and the capacity increase is more than 2 times. This phenomenon indicates that photogenerated carriers generated by illumination participate in the electrode reaction, providing additional electrochemical driving force for the insertion / extraction of zinc ions, thereby significantly improving the specific capacity and reaction kinetics of the material.

[0039] The self-charging curve of the light-induced self-charging aqueous zinc-ion battery prepared in this embodiment under light conditions is obtained, and the results are as follows: Figure 6 As shown. By Figure 6It can be seen that, without an external power source, the battery voltage can gradually increase from approximately 0.88V to 1.01V and stabilize when illuminated by a xenon lamp; while without xenon lamp illumination, the battery voltage remains almost at 1.03V. This process directly proves that light energy can drive the electrochemical reaction inside the battery, achieving self-charging. This design eliminates the dependence on traditional charging methods and provides a sustainable, self-powered energy storage solution for wearable devices, portable electronic devices, and other scenarios.

[0040] A self-charging example image of the light-induced self-charging aqueous zinc-ion battery prepared in this embodiment under sunlight conditions is obtained. Figure 7 This image shows an example of a self-charging aqueous zinc-ion battery under sunlight with its opaque side facing the sun. The open-circuit voltage was recorded at 1-hour intervals. The initial voltage was 1.066V, and after 5 hours of sunlight exposure, it only slightly increased to 1.068V. The voltage change was minimal, and the battery remained stable overall. This indicates that when the opaque side faces the sun, the light cannot effectively act on the internal photoactive layer, making it difficult to generate photogenerated carriers, and the battery can hardly achieve self-charging under sunlight.

[0041] Figure 8 This image shows an example of the self-charging behavior of a light-exposed self-charging aqueous zinc-ion battery under sunlight, with the light-transmitting side facing the sun. Samples were taken at 1-hour intervals. The initial voltage was 0.649V, steadily increasing with prolonged sunlight exposure: 0.70V after 1 hour, 0.840V and 0.923V after 2 and 3 hours respectively, 1.001V after 4 hours, and further increasing to 1.111V after 5 hours, exhibiting a significant time-dependent self-charging behavior. Figure 7 The results show a stark contrast, confirming that the photoresponse and self-charging capability of this battery are highly dependent on the light-transmitting surface. When the light-transmitting active layer is directly exposed to sunlight, it can efficiently absorb photons and generate photogenerated carriers, driving the zinc ion insertion / extraction process at the electrode interface, thus achieving efficient conversion and storage of light energy into chemical energy. This provides key experimental evidence for the development of novel sustainable self-charging aqueous zinc ion energy storage devices.

[0042] In summary, the combination of the V2O3@TiO2 hollow nanosphere cathode material and the transparent soft-pack battery of this invention successfully achieves the goal of self-charging using natural sunlight, opening up a new direction for the next generation of sustainable, self-powered aqueous zinc-ion energy storage devices, and is of great significance for the large-scale use of aqueous zinc-ion batteries.

[0043] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a light-illuminated self-charging aqueous zinc-ion battery device, characterized in that, Includes the following steps: S1. VO2 hollow nanospheres were prepared by hydrothermal method. TiO2 was coated on the surface of the VO2 hollow nanospheres by solution method and then calcined to obtain V2O3@TiO2 hollow nanospheres. S2. The V2O3@TiO2 hollow nanospheres, carbon nanotubes and polyvinylidene fluoride obtained in step S1 are mixed in proportion, dissolved evenly in solvent and then subjected to ultrasonic treatment; then, the slurry is coated onto graphite foil, and the graphite foil loaded with the material is dried to obtain the positive electrode sheet. S3. A rectangular light-transmitting hole is made in the positive electrode aluminum-plastic film shell, and the light-transmitting hole is covered with PET film, cured and sealed to form a transparent light-transmitting window, thus obtaining the aluminum-plastic film encapsulation material; S4. Using a glass fiber separator as the separator and zinc foil as the negative electrode, the positive electrode, glass fiber separator and negative electrode are stacked in sequence and then placed into an aluminum-plastic film encapsulation material. Electrolyte is injected and encapsulated to obtain a light-illuminated self-charging aqueous zinc-ion battery.

2. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 1, characterized in that, In step S1, the preparation method of V2O3@TiO2 hollow nanospheres is as follows: S11. Vanadium oxalate precursor powder is uniformly dissolved in the mixed solution, and then subjected to heating, cooling, centrifugation, washing and drying processes to obtain VO2 hollow nanospheres. S12. First, the prepared VO2 hollow nanospheres were ultrasonically dispersed in anhydrous ethanol, and then an aqueous surfactant solution was added and stirred vigorously to obtain a VO2 suspension. Tetrabutyl titanate was uniformly dissolved in the ethanol solution to obtain the reaction stock solution. The VO2 suspension was heated in a water bath, and then the reaction stock solution was slowly added dropwise to the VO2 suspension. After vigorous stirring, the mixture was subjected to aging, centrifugation, drying and calcination treatments in sequence to obtain V2O3@TiO2 hollow nanospheres.

3. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 2, characterized in that, In step S11, the mixed solution is prepared by methanol and water in a volume ratio of 4:1, and the solid-liquid ratio of vanadium oxalate precursor powder and mixed solution is 5:

6.

4. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 3, characterized in that, In step S12, the surfactant aqueous solution is a polyethylene glycol tert-octylphenyl ether aqueous solution; the solid-liquid ratio of VO2 hollow nanospheres to anhydrous ethanol is 30:50; the volume ratio of tetrabutyl titanate to anhydrous ethanol is 0.3:5; and the volume ratio of the reaction stock solution to the VO2 suspension is 1:

1.

5. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 4, characterized in that, In step S12, the calcination conditions are: 10℃ min -1 The temperature was increased to 400℃ and calcined for 15 minutes.

6. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 1, characterized in that, In step S2, the mass ratio of V2O3@TiO2 hollow nanospheres: carbon nanotubes: polyvinylidene fluoride is 7:2:1, and the solvent is N-methylpyrrolidone.

7. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 1, characterized in that, In step S3, an ITO layer is coated on the PET film, and before curing and sealing, the ITO layer of the PET film is positioned facing the inside of the positive electrode aluminum-plastic film shell; The curing and sealing process involves sequentially applying UV adhesive and UV laser curing.

8. The method for preparing a light-induced self-charging aqueous zinc-ion battery device according to claim 1, characterized in that, In step S4, a 3M zinc trifluoromethanesulfonate solution is used as the battery electrolyte.

9. A light-illuminated self-charging aqueous zinc-ion battery device, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.

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