A large-area photochargeable aqueous zinc-ion battery, its preparation method and application

Abstract

This invention discloses a large-area photo-chargeable aqueous zinc-ion battery, its preparation method, and its application. The method includes the following steps: Two pieces of glass with a transparent conductive layer coated on one side are taken. A positive electrode material is placed on the coated layer of one of the glass pieces. A glass fiber separator and a negative electrode material are sequentially covered on top of the positive electrode material. The other glass piece is then placed on top of the negative electrode material with its coated layer facing down. The positions of the two glass pieces are adjusted so that they are stacked alternately. Pressure is applied to the resulting stacked structure, and three sides are sealed with hot melt adhesive. After the hot melt adhesive has cured, electrolyte is injected into the unsealed side, and then this side is sealed again. The negative electrode of a diode is connected to the glass on the positive electrode side of the battery, and the positive electrode of the diode is connected to the glass on the negative electrode side of the battery, thus obtaining a large-area photo-chargeable aqueous zinc-ion battery. The battery of this invention has the advantages of high light utilization, stable charging, and low loss.

Description

Technical Field

[0001] This invention relates to the fields of materials science and electrochemistry, specifically to a large-area photochargeable aqueous zinc-ion battery, its preparation method, and its application. Background Technology

[0002] With its inherent advantages of unlimited reserves, wide distribution, and convenient access, solar energy has become a core research direction in the current energy field. However, solar energy is characterized by significant intermittency and volatility, which places key demands on supporting energy storage technologies: not only must efficient energy storage be achieved, but it must also be closely coordinated with the solar energy collection process to ensure a stable energy supply.

[0003] In traditional solutions, solar energy collection devices and energy storage systems are often separate entities, requiring additional connection circuits for energy transfer. This separation not only results in high energy conversion losses but also leads to low overall system integration, large space requirements, and difficulty in adapting to miniaturized and high-efficiency applications. The dual-electrode integrated system, however, integrates the light absorption layer and energy storage electrode into a single device, directly eliminating the need for additional connection circuits in traditional solutions. This significantly reduces energy losses while improving system integration and space utilization.

[0004] Photo-chargeable aqueous zinc-ion batteries are typical dual-electrode systems. They combine a light-absorbing layer with an aqueous zinc-ion battery energy storage system to create a self-charging energy storage system that can directly utilize solar energy. The core of this system is the use of a bifunctional material with both photoelectric response and zinc storage capabilities as the positive electrode. Under illumination, light energy is converted into chemical energy through a photogenerated carrier separation mechanism, while energy storage is achieved through the insertion / extraction reactions of zinc ions. In this process, the transmittance of incident light directly affects the photogenerated carrier generation efficiency, while the light-receiving area of ​​the photoactive material determines the total amount of light energy captured. Both factors together constitute key factors influencing the battery's photocharging efficiency and energy storage performance.

[0005] Currently, most photoelectric-chargeable zinc-ion batteries adopt an open-cell button cell structure. Its core components consist of a perforated metal positive electrode shell, positive electrode material, separator, electrolyte, and negative electrode shell. While this structure meets the basic requirements for light injection, it has several limitations: the metal shell's obstruction results in low overall light transmittance, and the photoactive area is strictly limited by the opening size, directly restricting light absorption efficiency and photoelectric conversion effect. More importantly, there are two core circuit problems during photoelectric charging: firstly, it is difficult to form an effective external circuit; secondly, when using a simple external ohmic resistor to form an external circuit, not only will a large reverse leakage current occur during the photoelectric charging stage, but self-discharge will also occur during the discharge stage, further exacerbating performance loss.

[0006] Due to the multiple defects of existing perforated button structures (limited optical performance and issues such as leakage current and self-discharge at the circuit level), they generally exhibit low transmittance, small photoactive area, low capacity, and poor cycle life, making it difficult to meet the comprehensive performance requirements of practical applications. Therefore, developing a novel battery structure that combines high transmittance, large photoactive area, high specific capacity, long cycle life, and efficient external circuitry with low self-discharge characteristics has become a key area urgently needing breakthroughs in the field of photovoltaic-chargeable aqueous zinc-ion batteries. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a large-area photo-chargeable aqueous zinc-ion battery, its preparation method, and its applications. This invention eliminates metal shell obstruction by using a high-transmittance glass outer shell, increasing the photoactive area to improve light absorption efficiency; simultaneously, it combines a protection circuit to regulate the charging and discharging process, suppressing reverse leakage current and preventing self-discharge, ultimately achieving synergistic optimization of high light utilization, stable charging, and low loss, thus breaking through the bottlenecks of existing technologies.

[0008] To achieve the above objectives, the technical solution designed by the present invention is as follows:

[0009] This invention provides a method for preparing a large-area photochargeable aqueous zinc-ion battery, comprising the following steps:

[0010] (1) Take two pieces of glass with a transparent conductive layer on one side, and place the positive electrode material on the coating layer of one of the pieces of glass;

[0011] (2) Cover the positive electrode material with a glass fiber membrane and a zinc negative electrode in sequence, and then cover the zinc negative electrode with another piece of glass with the coating facing down, and adjust the position so that the two pieces of glass are stacked alternately.

[0012] (3) Apply pressure to the composite structure obtained in step (2) and seal three sides of it with hot melt adhesive;

[0013] (4) After the hot melt adhesive has cured, inject electrolyte into the unsealed side and then seal that side;

[0014] (5) After the hot melt adhesive has cured, connect the negative electrode of the diode to the glass on the positive electrode side of the battery, and connect the positive electrode of the diode to the glass on the negative electrode side of the battery to obtain a large-area photoelectric charging aqueous zinc-ion battery.

[0015] Further, in step (1), the transparent conductive layer is any one of indium tin oxide layer, fluorine-doped tin oxide layer and aluminum-doped zinc oxide layer;

[0016] It also includes a pretreatment step for the glass with indium tin oxide plated on one side: wiping the plated surface of the glass with anhydrous ethanol.

[0017] The positive electrode material is V6O. 13 and V6O 13 Any of @NiO.

[0018] Furthermore, the transparent conductive layer is an indium tin oxide layer; the positive electrode material is V6O. 13 @NiO;

[0019] V6O 13 The preparation method of @NiO is as follows:

[0020] ① Vanadium pentoxide and oxalic acid dihydrate were dissolved in water, heated and stirred, and then subjected to a hydrothermal reaction. After the reaction was completed, the mixture was cooled, filtered to obtain a precipitate, and the precipitate was dried to obtain V6O. 13 powder;

[0021] ② V6O 13 Powder, acetylene black, and PVDF emulsion are mixed to prepare a slurry, yielding V6O. 13 Slurry;

[0022] ③ V6O 13 The slurry was drop-coated onto a titanium mesh, and after drying, the NiO dispersion was drop-coated onto V6O. 13 The slurry surface is dried again to obtain V6O. 13 @NiO.

[0023] Furthermore, in step ①, the mass ratio of vanadium pentoxide to oxalic acid dihydrate is 1.6~2∶1~1.4, the heating temperature is 60~90°C, the stirring time is 45~75 min, the hydrothermal reaction temperature is 160~200°C, the hydrothermal reaction time is 160~200 min, the drying temperature is 45~75°C, and the drying time is 18~30 h;

[0024] In step ②, the solid content of the PVDF emulsion is 9.5~11.5 mg / mL, and the V6O content is... 13 The mass ratio of powder, acetylene black and PVDF emulsion is 7:2:1;

[0025] In step ③, the concentration of NiO dispersion is 15~25 mol / L, and V6O 13 The volume ratio of slurry to NiO dispersion for drop coating is 2~4:3~5, the drying temperature is 45~75°C, and the drying time is 18~30 h.

[0026] Furthermore, in step (2), the glass fiber membrane is any one of GF / A glass fiber membrane, GF / D glass fiber membrane, and GF / F glass fiber membrane;

[0027] The staggered width of the two glass pieces stacked alternately is 1~1.5 cm. The area of ​​the overlapping part of the two glass pieces is greater than the area of ​​the glass fiber separator, which is greater than the area of ​​the positive electrode material, which is greater than the area of ​​the zinc negative electrode.

[0028] Furthermore, in step (3), the hot melt adhesive is an ethylene-vinyl acetate copolymer-based hot melt adhesive; the applied pressure is 0.5~1.5 MPa; and the curing time of the hot melt adhesive is 2~3 min.

[0029] Furthermore, the applied pressure is 1 MPa; the hot melt adhesive curing time is 2 min.

[0030] Furthermore, in step (4), the electrolyte is any one of zinc trifluoromethanesulfonate electrolyte, zinc sulfate electrolyte, and zinc chloride electrolyte, and the concentration of the electrolyte is 2.5~3.5 mol / L; 65~70 μL of electrolyte is injected per square centimeter of diaphragm.

[0031] Furthermore, the electrolyte is zinc trifluoromethanesulfonate electrolyte with a concentration of 3 mol / L; 66.1 μL of electrolyte is injected per square centimeter of diaphragm.

[0032] Furthermore, in step (5), the reverse cutoff voltage of the diode is 15~30 V, and the reverse leakage current is 0.5~5 μA.

[0033] Furthermore, the diode has a reverse cutoff voltage of 20 V and a reverse leakage current of 1 μA.

[0034] The present invention also provides a large-area photochargeable aqueous zinc-ion battery prepared by the preparation method described above.

[0035] The present invention also provides an application of the large-area photoelectric charging aqueous zinc-ion battery described above in the field of solar photoelectric charging energy storage.

[0036] The principle of this invention:

[0037] Using glass with a single-sided transparent conductive layer as the battery casing achieves two core functions: First, leveraging the high light transmittance and large surface area of ​​the glass, an efficient light incident channel is constructed, maximizing the light-receiving area of ​​the photoactive material and enhancing light energy capture and conversion efficiency. Second, utilizing the good conductivity of the transparent conductive layer reduces the transmission impedance of photogenerated electrons, minimizing energy loss and providing a foundation for the efficient utilization of photogenerated electrons. Furthermore, a stepped gap is formed through a cross-overlapping structural design, significantly improving the sealing performance of the hot melt adhesive encapsulation. Simultaneously, the staggered areas between the two glass panels allow for space to be reserved for connecting the testing system, optimizing the convenience of subsequent testing operations.

[0038] The beneficial effects of this invention are:

[0039] 1. This invention innovatively uses glass with a single-sided transparent conductive layer (such as ITO) as the battery casing, giving full play to its material properties and structural synergistic advantages: On the one hand, the glass substrate itself has an ultra-high light transmittance of >90%, and combined with the large-area metal-free structural design, it completely eliminates the loss of photoactive area caused by the metal casing and opening limitation of traditional open-hole button batteries, which significantly expands the effective light-receiving area of ​​the positive electrode active material, and simultaneously enhances the number and efficiency of photogenerated charge carriers; on the other hand, the low sheet resistance (<10 Ω / sq) of the transparent conductive layer on the glass surface provides a low-loss transmission path for photogenerated electrons, reduces electron migration resistance, improves charge collection efficiency, and reduces energy dissipation. It synergistically enhances the photoelectric conversion performance of the battery from the two key links of light absorption and charge transport, laying the physical foundation for efficient photocharging.

[0040] 2. Addressing the core pain points of "difficulty in forming an effective circuit during the photoelectric charging stage" and "easy occurrence of reverse leakage current and self-discharge due to external ohmic resistors" in the photoelectric charging process of aqueous zinc-ion batteries, this invention innovatively connects a diode with high reverse cutoff voltage (15~30 V) and low reverse leakage current (0.5~5 μA) to the battery casing, achieving bidirectional precise control of the photoelectric charging-discharging process: During the photoelectric charging stage, the diode is in a unidirectional conducting state, ensuring efficient migration of photogenerated electrons from the positive electrode to the negative electrode to complete charging, while suppressing the reverse leakage current to below the microampere level, ensuring the stability of the charging process; During the discharging stage, the diode remains in an open circuit state, completely blocking the external circuit and avoiding energy loss due to self-discharge. This simultaneously optimizes the photoelectric charging efficiency and energy utilization rate at the circuit level, significantly extending the actual usable capacity of the battery.

[0041] 3. Addressing the technical challenge of balancing sealing performance and process efficiency in battery module encapsulation, this invention innovatively uses ethylene-vinyl acetate copolymer (EVA)-based hot melt adhesive as the encapsulation material. Through synergistic optimization of material properties and structural design, it achieves dual objectives: EVA hot melt adhesive exhibits high fluidity after heating and melting, rapidly penetrating and filling the minute gaps between glass, electrodes, and separators. Combined with a stepped encapsulation gap structure, it enhances mechanical interlocking force. After cooling, it solidifies in just 2-3 minutes to form a continuous and dense sealing layer. Compared to traditional epoxy resin encapsulation (requiring high-temperature baking for over 2 hours), the total encapsulation time for a single battery is reduced to less than 6 minutes, significantly lowering time costs. The cured EVA adhesive layer effectively blocks the penetration of external corrosive factors such as moisture and oxygen, providing long-term stable protection for the internal components of the battery and significantly extending cycle life. Attached Figure Description

[0042] Figure 1 A schematic diagram of a large-area photoelectric charging aqueous zinc-ion battery;

[0043] Figure 2 A physical image of a large-area photo-charged aqueous zinc-ion battery without an external diode;

[0044] Figure 3 A schematic diagram showing the connection of a large-area photochargeable aqueous zinc-ion battery to a test system;

[0045] In the diagram, 1. Indium tin oxide conductive glass; 2. Positive electrode; 3. Separator; 4. Negative electrode; 5. Diode;

[0046] Figure 4 The working circuit diagram for connecting the time-rechargeable aqueous zinc-ion battery D1 (without external circuitry) to the test system;

[0047] Figure 5 The working circuit diagram for connecting the D2 time-charging aqueous zinc-ion battery with an external ohmic resistor to the test system;

[0048] Figure 6 The connection circuit diagram between the large-area photochargeable aqueous zinc-ion battery 2 and the test system when an external diode is used as a protection circuit.

[0049] Figure 7 Photochart showing the photocharging performance of the large-area photocharging aqueous zinc-ion battery 2 prepared in Example 2, which is charged by light alone;

[0050] Figure 8 Photocharging performance of D2, an aqueous zinc-ion battery with an external ohmic resistor prepared for Comparative Example 2, relying solely on light for charging;

[0051] Figure 9 The large-area photo-charged aqueous zinc-ion battery 3 prepared in Example 3 shows its photo-charging performance under light irradiation alone. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can understand it.

[0053] Example 1

[0054] Preparation method of large-area photocharged aqueous zinc-ion battery 1

[0055] 1. Combination Figures 1-2 As shown, take two pieces of glass with a transparent conductive layer on one side, and place the positive electrode material on the coating layer of one of the pieces of glass.

[0056] 2. Cover the positive electrode material with a glass fiber diaphragm and a zinc negative electrode in sequence, and then cover the zinc negative electrode with another piece of glass with the coating side down, and adjust the position so that the two pieces of glass are stacked alternately.

[0057] 3. Apply pressure to the composite structure obtained in step 2 and seal three sides with hot melt adhesive;

[0058] 4. After the hot melt adhesive has cured, inject electrolyte into the unsealed side and then seal that side.

[0059] 5. After the hot melt adhesive has cured, connect the negative terminal of the diode to the glass on the positive terminal side of the battery, and connect the positive terminal of the diode to the glass on the negative terminal side of the battery to obtain a large-area photoelectric charging aqueous zinc-ion battery 1.

[0060] In this embodiment:

[0061] (1) In step 1, the transparent conductive layer is any one of indium tin oxide layer, fluorine-doped tin oxide layer and aluminum-doped zinc oxide layer; it also includes a pretreatment step for glass with indium tin oxide plated on one side: wiping the plated surface of the glass with anhydrous ethanol; the positive electrode material is V6O 13 and V6O 13 Any of @NiO.

[0062] V6O 13 The preparation method of @NiO is as follows:

[0063] ① Dissolve 3.2–4.0 g of vanadium pentoxide and 2.0–2.8 g of oxalic acid dihydrate in 80 ml of deionized water. Heat and stir at 60–90°C for 45–75 min. Then, carry out a hydrothermal reaction at 160–200°C for 160–200 min. After the reaction is complete, cool to room temperature, filter to obtain a precipitate, and dry the precipitate to obtain V6O. 13 Powder; drying temperature 45~75°C, drying time 18~30 h;

[0064] ② V6O 13 Powder, acetylene black, and PVDF emulsion (solid content 9.5–11.5 mg / mL) were mixed in a mass ratio of 7:2:1 to prepare a slurry, yielding V6O with a concentration of 1.05 mg / mL. 13 Slurry;

[0065] ③ V6O 13 The slurry was drop-coated onto a titanium mesh and dried. Then, a NiO dispersion (concentration of 15~25 mol / L) was drop-coated onto V6O. 13 The slurry surface is dried again to obtain V6O. 13 @NiO;V6O 13 The volume ratio of slurry to NiO dispersion for drop coating is 2~4:3~5, the drying temperature is 45~75°C, and the drying time is 18~30 h.

[0066] (2) In step 2, the glass fiber diaphragm is any one of GF / A glass fiber diaphragm (Shanghai Ximeng Technology Co., Ltd.), GF / D glass fiber diaphragm (Xinweiyanxuan) and GF / F glass fiber diaphragm (GE Healthcare);

[0067] The staggered width of the two glass pieces stacked alternately is 1~1.5 cm. The area of ​​the overlapping part of the two glass pieces is greater than the area of ​​the glass fiber separator, which is greater than the area of ​​the positive electrode material, which is greater than the area of ​​the zinc negative electrode.

[0068] (3) In step 3, the hot melt adhesive is an ethylene-vinyl acetate copolymer-based hot melt adhesive; the applied pressure is 0.5~1.5 MPa; and the hot melt adhesive curing time is 2~3 min.

[0069] (4) In step 4, the electrolyte is any one of zinc trifluoromethanesulfonate electrolyte, zinc sulfate electrolyte and zinc chloride electrolyte, and the concentration of the electrolyte is 2.5~3.5 mol / L; 65~70 μL of electrolyte is injected per square centimeter of diaphragm.

[0070] (5) In step 5, the reverse cutoff voltage of the diode is 15~30 V and the reverse leakage current is 0.5~5 μA.

[0071] Example 2

[0072] Preparation method of large-area photochargeable aqueous zinc-ion battery 2

[0073] 1. Pretreatment of Indium Tin Oxide Conductive Glass: Take two pieces of quartz glass (7.0 × 7.0 cm) with an indium tin oxide (ITO) layer on one side. 2 Place both pieces of glass on clean weighing paper, ensuring the coated surface faces upwards. Use lint-free paper dampened with anhydrous ethanol to wipe the coated surfaces of both glass pieces 2-3 times to remove surface dust, oil, and impurities, ensuring good contact at the interface.

[0074] 2. Preparation of cathode material: Following the steps in Example 1, first prepare 300 μL of V6O 13 The slurry was uniformly drop-coated onto a square titanium mesh with a side length of 5 cm and dried at 60°C for 24 h; then 400 μL of NiO dispersion was drop-coated onto V6O. 13 The slurry surface is then dried again.

[0075] 3. Positive electrode material laying: Place the positive electrode material from step 2 onto one of the 7.0 × 7.0 cm pieces from step 1. 2 On the coating of indium tin oxide conductive glass.

[0076] 4. Battery Component Stacking: First, take a 5.5 cm square glass fiber separator (GF / D glass fiber separator) and place it over the positive electrode material prepared in step 3, ensuring that the separator completely covers the positive electrode material and that there are no wrinkles at the edges; next, place a 4.0 cm square zinc negative electrode (zinc metal sheet) flat on top of the glass fiber separator, ensuring that the zinc negative electrode and the positive electrode material are aligned vertically; finally, take another 7.0 × 7.0 cm piece pretreated in step 1. 2 Two indium tin oxide (ITO) conductive glasses are placed on top of a zinc negative electrode with the plated surface facing down. Their positions are adjusted so that the two ITO conductive glasses are stacked alternately, with a staggered width of 1.0 cm, and the overlapping area of ​​the two ITO conductive glasses is 6.0 × 6.0 cm. 2 The overlapping portion is covered with a glass fiber diaphragm.

[0077] 5. Structural Encapsulation (Three Sides): Apply a uniform pressure of 1 MPa (pressure uniformity ≥98%) above the indium tin oxide (ITO) conductive glass on the negative electrode side to ensure tight adhesion between the ITO conductive glass, positive electrode, separator, zinc negative electrode, and the ITO conductive glass on the negative electrode side. The distance between the two ITO conductive glass pieces should be measured to be 2.0 mm. Then, use a hot melt gun to heat ethylene-vinyl acetate copolymer (EVA) based hot melt adhesive to encapsulate three sides of the above-mentioned bonded structure. During encapsulation, ensure the hot melt adhesive evenly covers the edges without gaps or air bubbles. After encapsulation, allow the structure to stand for 2.5 minutes to allow the hot melt adhesive to fully cure.

[0078] 6. Electrolyte Injection and Full Encapsulation: Accurately pipette 2.0 mL of 3 mol / L zinc trifluoromethanesulfonate electrolyte and slowly inject it into the battery from the unencapsulated side, avoiding electrolyte overflow during the injection process. After the electrolyte has completely penetrated the separator, use a hot melt gun to encapsulate the unencapsulated side with EVA-based hot melt adhesive. After encapsulation, allow it to stand for 2.5 min to ensure the hot melt adhesive has cured.

[0079] 7. Diode processing: Take a diode with a reverse cutoff voltage of 20 V and a reverse leakage current of 1.0 μA, and bend the two leads at 90° in the same direction to ensure that the bending angle and direction of the leads are completely consistent.

[0080] 8. Diode connection: First, connect the processed diode negative electrode to the indium tin oxide conductive glass on the positive electrode side of the battery, and connect the positive electrode to the indium tin oxide conductive glass on the negative electrode side of the battery to complete the preparation of the large-area photochargeable aqueous zinc-ion battery 2.

[0081] Then the test system was taken out and combined with Figure 3As shown, by connecting the matching test leads with alligator clips to the indium tin oxide conductive glass on the positive and negative sides of the battery respectively, the photocharging performance test can be carried out.

[0082] The results are as follows Figure 7 As shown, this embodiment uses V6O 13 Using NiO as the cathode material, a large-area photochargeable aqueous zinc-ion battery based on a glass casing and protection circuit was assembled, achieving a performance of 70 mW / cm². 2 After being photocharged for 1 hour under intense light irradiation and then discharged at a current density of 100 mA / g, the photoactive area of ​​this large-area photochargeable aqueous zinc-ion battery 2 is 5.0 × 5.0 cm². 2 It can achieve 10 reversible cycles with a reversible capacity of 85.5 mAh / g.

[0083] Comparative Example 1

[0084] Preparation method of photo-chargeable aqueous zinc-ion battery D1

[0085] The preparation method of the photo-charged aqueous zinc-ion battery D1 in this comparative example is the same as that in Example 2, except that steps 7 and 8 are not performed, i.e., no external diode is connected.

[0086] The performance of the D1 photo-chargeable aqueous zinc-ion battery of this comparative example was tested at 70 mW / cm. 2 After being photocharged for 1 hour under intense light irradiation and then discharged at a current density of 100 mA / g, the photoactive area of ​​this photocharged aqueous zinc-ion battery D1 is 5.0 × 5.0 cm². 2 It can only cycle once, and its reversible capacity is only 22.3 mAh / g.

[0087] Comparative Example 2

[0088] Preparation method of photo-chargeable aqueous zinc-ion battery D2

[0089] The preparation method of the photo-charged aqueous zinc-ion battery D2 in this comparative example is the same as that in Example 2, except that in steps 7 and 8, the diode is replaced with an ohmic resistor with a resistance of 2000 Ω.

[0090] The performance of the D2 photo-chargeable aqueous zinc-ion battery of this comparative example was tested, and the results are as follows: Figure 8 As shown, at 70 mW / cm 2 After being photocharged for 1 hour under intense light irradiation and then discharged at a current density of 100 mA / g, the photoactive area of ​​this photocharged aqueous zinc-ion battery D2 is 5.0 × 5.0 cm². 2 It can only cycle 10 times, and its reversible capacity is only 30.1 mAh / g.

[0091] Combination Figures 4-6As shown, without an external circuit, the photogenerated carriers (photoelectrons) generated at the positive electrode lack a transport path and cannot migrate to the negative electrode to achieve an effective reduction reaction. They can only participate in the first charge cycle through light-induced side reactions, thus limiting the cycle to one time with a specific capacity of only 22.3 mAh / g. While an external ohmic resistor can form an external circuit channel, allowing the photocharging process to continue for up to 10 cycles, severe leakage current causes significant loss of photogenerated carriers during transport, resulting in a still low photocharging capacity. However, when an external diode is connected, not only is a complete external circuit constructed, but the diode's unidirectional conduction characteristic effectively suppresses leakage current. This improvement significantly increases the first-cycle photocharging capacity to 85.5 mAh / g, and maintains a capacity of 22.2 mAh / g after 10 cycles, greatly enhancing both photocharging performance and cycle stability.

[0092] Example 3

[0093] Preparation method of large-area photochargeable aqueous zinc-ion battery 3

[0094] 1. Pretreatment of Indium Tin Oxide Conductive Glass: Take two pieces of quartz glass (10.0 × 10.0 cm) with an indium tin oxide coating on one side. 2 The same process as step 1 in Example 2 is followed.

[0095] 2. Preparation of positive electrode material: Following the steps in Example 1, first prepare 810 μL of V6O 13 The slurry was uniformly drop-coated onto a square titanium mesh with a side length of 8 cm and dried at 60°C for 24 h; then 1080 μL of NiO dispersion was drop-coated onto V6O. 13 The slurry surface is then dried again.

[0096] 3. Positive electrode material laying: Place the positive electrode material prepared in step 2 onto one of the 10.0 × 10.0 cm pieces from step 1. 2 On the indium tin oxide conductive glass coating, adjust the position of the positive electrode material so that the center of the positive electrode material is 4.5 cm from one side of the indium tin oxide conductive glass and 5.0 cm from the other adjacent side. After placing it stably, press it gently to ensure good contact between the positive electrode material and the indium tin oxide conductive glass coating.

[0097] 4. Battery Component Stacking: First, take a square glass fiber separator (GF / D glass fiber separator) with a side length of 8.5 cm and cover it on top of the positive electrode material prepared in step 2, ensuring that the separator completely covers the positive electrode material and that there are no wrinkles at the edges; next, place a zinc metal sheet with a side length of 5.0 cm flat on top of the separator, ensuring that the zinc negative electrode and the positive electrode material are aligned vertically; finally, take another 10.0 × 10.0 cm sheet pretreated in step 1. 2Two indium tin oxide (ITO) conductive glasses are placed on top of a zinc negative electrode with the plated surface facing down. Their positions are adjusted so that the two ITO conductive glasses are stacked alternately, with a staggered width of 1.0 cm, and the overlapping area of ​​the two ITO conductive glasses is 9.0 × 9.0 cm. 2 The overlapping portion is covered with a glass fiber diaphragm.

[0098] 5. Structural Encapsulation (Three Sides): Apply a uniform pressure of 1 MPa (pressure uniformity ≥98%) above the indium tin oxide (ITO) conductive glass on the negative electrode side to ensure tight adhesion between the ITO conductive glass, positive electrode, separator, zinc negative electrode, and the ITO conductive glass on the negative electrode side. The distance between the two ITO conductive glass pieces should be measured to be 2.0 mm. Then, use a hot melt gun to heat ethylene-vinyl acetate copolymer (EVA) based hot melt adhesive to encapsulate three sides of the above-mentioned bonded structure. During encapsulation, ensure the hot melt adhesive evenly covers the edges without gaps or air bubbles. After encapsulation, allow the structure to stand for 2.5 minutes to allow the hot melt adhesive to fully cure.

[0099] 6. Electrolyte Injection and Full Encapsulation: Using a pipette, accurately pipette 4.8 mL of 3 mol / L zinc trifluoromethanesulfonate electrolyte and slowly inject it into the battery from the unencapsulated side, avoiding electrolyte overflow during the injection process. After the electrolyte has completely penetrated the separator, use a hot melt gun to encapsulate the unencapsulated side with EVA-based hot melt adhesive. After encapsulation, allow it to stand for 2.5 min to ensure the hot melt adhesive has cured.

[0100] 7. Diode processing: Take a diode with a reverse cutoff voltage of 20 V and a reverse leakage current of 1.0 μA, and bend the two leads at 90° in the same direction to ensure that the bending angle and direction of the leads are completely consistent.

[0101] 8. Diode connection: First, connect the processed diode negative electrode to the indium tin oxide conductive glass on the positive electrode side of the battery, and connect the positive electrode to the indium tin oxide conductive glass on the negative electrode side of the battery to complete the preparation of the large-area photochargeable aqueous zinc-ion battery 3.

[0102] The results are as follows Figure 9 As shown, this embodiment uses V6O 13 @NiO was used as the cathode material to assemble a glass structure for a large-area photovoltaic-chargeable aqueous zinc-ion battery, achieving a voltage of 70 mW / cm². 2 After photocharging for 1 hour under intense light irradiation, followed by discharging at a current density of 100 mA / g, the photoactive area of ​​the glass structure is 8.0 × 8.0 cm². 2 It can achieve 10 reversible cycles with a reversible capacity of 64.8 mAh / g.

[0103] All other parts not described in detail are existing technologies. Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a large-area photochargeable aqueous zinc-ion battery, characterized in that: Includes the following steps: (1) Take two pieces of glass with a transparent conductive layer on one side, and place the positive electrode material on the coating layer of one of the pieces of glass; (2) Cover the positive electrode material with a glass fiber membrane and a zinc negative electrode in sequence, and then cover the zinc negative electrode with another piece of glass with the coating facing down. Adjust the position so that the two pieces of glass are stacked in an alternating manner. The offset width of the two pieces of glass is 1~1.5 cm. The area of ​​the overlapping part of the two pieces of glass is greater than the area of ​​the glass fiber membrane, which is greater than the area of ​​the positive electrode material, which is greater than the area of ​​the zinc negative electrode. (3) Apply pressure to the composite structure obtained in step (2) and seal three sides of it with hot melt adhesive; (4) After the hot melt adhesive has cured, inject electrolyte into the unsealed side and then seal that side; (5) After the hot melt adhesive has cured, connect the negative terminal of the diode to the glass on the positive terminal side of the battery and connect the positive terminal of the diode to the glass on the negative terminal side of the battery to obtain a large-area photochargeable aqueous zinc-ion battery. The positive electrode material is V6O. 13 @NiO; The V6O 13 The preparation method of @NiO is as follows: ① Vanadium pentoxide and oxalic acid dihydrate were dissolved in water, heated and stirred, and then subjected to a hydrothermal reaction. After the reaction was completed, the mixture was cooled, filtered to obtain a precipitate, and the precipitate was dried to obtain V6O. 13 powder; ② V6O 13 Powder, acetylene black, and PVDF emulsion are mixed to prepare a slurry, yielding V6O. 13 Slurry; ③ V6O 13 The slurry was drop-coated onto a titanium mesh, and after drying, the NiO dispersion was drop-coated onto V6O. 13 The slurry surface is dried again to obtain V6O. 13 @NiO.

2. The preparation method according to claim 1, characterized in that: In step (1), the transparent conductive layer is any one of indium tin oxide layer, fluorine-doped tin oxide layer and aluminum-doped zinc oxide layer; It also includes a pretreatment step for the glass with indium tin oxide plated on one side: wiping the plated surface of the glass with anhydrous ethanol.

3. The preparation method according to claim 2, characterized in that: The transparent conductive layer is an indium tin oxide layer.

4. The preparation method according to claim 1, characterized in that: In step (2), the glass fiber membrane is any one of GF / A glass fiber membrane, GF / D glass fiber membrane and GF / F glass fiber membrane.

5. The preparation method according to claim 1, characterized in that: In step (3), the hot melt adhesive is an ethylene-vinyl acetate copolymer-based hot melt adhesive; the applied pressure is 0.5~1.5 MPa; and the curing time of the hot melt adhesive is 2~3 min.

6. The preparation method according to claim 1, characterized in that: In step (4), the electrolyte is any one of zinc trifluoromethanesulfonate electrolyte, zinc sulfate electrolyte, and zinc chloride electrolyte, and the concentration of the electrolyte is 2.5~3.5 mol / L; 65~70 μL of electrolyte is injected per square centimeter of diaphragm.

7. The preparation method according to claim 6, characterized in that: The electrolyte is zinc trifluoromethanesulfonate electrolyte with a concentration of 3 mol / L; 66.1 μL of electrolyte is injected per square centimeter of diaphragm.

8. The preparation method according to claim 1, characterized in that: In step (5), the reverse cutoff voltage of the diode is 15~30V and the reverse leakage current is 0.5~5 μA.

9. A large-area photochargeable aqueous zinc-ion battery prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the large-area photoelectric charging aqueous zinc-ion battery as described in claim 9 in the field of solar photoelectric charging energy storage.

Images