Solid-state zinc-air battery and preparation method thereof

Abstract

The invention discloses a solid-state zinc-air battery and a preparation method thereof. The solid-state zinc-air battery comprises a catalyst positive electrode, a conductive titanium sheet, carrier gel and a battery negative electrode, and a catalyst of the catalyst positive electrode is formed by dispersing metal iridium on the surface of reduced graphene oxide; and the surface of the battery negative electrode is provided with a protective film with the thickness of 50-120nm. According to the invention, metal iridium is uniformly distributed on the surface of porous reduced graphene oxide and in holes, a metal catalyst is anchored on the surface of rGO, and loss of Ir is inhibited, so that precise regulation and control of oxygen adsorption capacity are realized, the catalytic effect of the battery is improved, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of novel solid-state battery technology, specifically to a solid-state zinc-air battery and its preparation method. Background Technology

[0002] With the large-scale development of renewable energy sources such as solar and wind power, the development of energy storage devices has received widespread attention. While lithium-ion batteries dominate the mainstream energy storage market, they suffer from low energy density, high cost, and insufficient safety (such as susceptibility to thermal runaway), making it difficult to meet the demands of future high-energy-density energy storage and special scenarios (such as flexible electronics). Traditional zinc-air batteries also face numerous problems, including safety issues and poor structural adaptability. Solid-state zinc-air batteries, with their advantages of high energy density, environmental friendliness, low cost, high safety, and strong structural flexibility, are considered one of the important candidate technologies for renewable energy storage.

[0003] However, solid-state zinc-air batteries are more susceptible to corrosion than liquid zinc-air batteries during operation, and their side reactions are more severe under the same conditions, accelerating battery aging. Furthermore, because solid-state zinc-air batteries use gel as the electrolyte carrier, while liquid zinc-air batteries require no carrier, the ionic conductivity of solid-state zinc-air batteries is significantly lower than that of liquid zinc-air batteries. This increases the battery voltage under constant current conditions, further increasing side reactions. Therefore, protecting the negative electrode of solid-state zinc-air batteries to extend battery life, while simultaneously optimizing battery catalysts at low cost to promote positive reactions and suppress side reactions, are the most significant challenges currently faced.

[0004] To address the aforementioned issues with current solid-state zinc-air batteries, the published paper "Photothermal-boosted flexible rechargeable zinc-air battery based on Ni-doped Mn3O4 with excellent low-temperature adaptability" (Carbon Energy; Wengai Guo, Fan Gu et al.; 2024.5.26) utilizes nickel-doped Mn3O4 / N-doped reduced graphene oxide (Ni-Mn3O4 / N-rGO) nanohybrids as bifunctional electrocatalysts. This photothermally promoted aqueous flexible zinc-air battery exhibits higher performance over a wide temperature range. Under near-infrared irradiation, Ni-Mn3O4 / N-rGO displays a strong photothermal effect, leading to an immediate local temperature rise in the electrodes. However, zinc-air batteries using this catalyst have several drawbacks. First, they operate in harsh environments, requiring photothermal assistance to achieve optimal results, severely limiting their application scenarios and necessitating additional light sources during operation. Second, the catalyst's effectiveness relies on photothermal effects to provide efficient localized heating, while the battery in question is an aqueous zinc-air battery, a semi-open battery system. Increased localized temperatures undoubtedly accelerate electrolyte evaporation, impacting battery performance and further affecting battery life. Third, excessive manganese intake can accumulate in the body (especially in the liver, kidneys, and brain), interfering with the normal functions of the nervous, digestive, and hematopoietic systems. Long-term exposure may lead to chronic manganese poisoning, limiting its application in flexible wearable devices and smart medical in-body monitoring.

[0005] In summary, it is of great significance to obtain a solid-state zinc-air battery that can achieve good overall performance, including high catalytic efficiency, suppression of side reactions, and long lifespan. Therefore, this patent application is filed. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a solid-state zinc-air battery and a method for its preparation.

[0007] The present invention adopts the following technical solution: The first objective of this invention is to provide a solid zinc-air battery, comprising a catalyst positive electrode, a conductive titanium sheet, a carrier gel, and a battery negative electrode, wherein the catalyst of the catalyst positive electrode is formed by dispersing metallic iridium on the surface of reduced graphene oxide. The surface of the negative electrode of the battery has a protective film with a thickness of 50~120nm.

[0008] The catalytic positive electrode in this invention catalyzes the main reaction of the zinc-air battery, improving battery performance while suppressing internal side reactions. As a window for air exchange between the zinc-air electrode and the outside environment, it must ensure permeability. A conductive titanium sheet facilitates electron exchange between the battery's positive electrode and the external environment. A gel electrolyte carrier holds the electrolyte necessary for battery operation and transports water. A protective film adheres to the surface of the zinc negative electrode to protect it from corrosion.

[0009] In this invention, an Ir-rGO (reduced graphene oxide) cathode catalyst is constructed, forming a gas-solid-liquid three-phase interface. This provides a more unobstructed oxygen channel and electrolyte wetting channel for battery operation, effectively promoting efficient charge and discharge processes. Simultaneously, the Ir-C bond formed between Ir and rGO anchors the metal catalyst to the rGO surface: on the one hand, it prevents metal catalyst aggregation, allowing more active sites to be exposed to the electrolyte, significantly improving catalytic efficiency; on the other hand, it inhibits Ir loss, preventing catalyst deactivation and battery failure caused by Ir loss. Furthermore, the Ir-C bond enables precise control of oxygen adsorption capacity—by adjusting the d-band center of Ir through rGO, the catalyst's oxygen adsorption is optimized: weak adsorption leads to insufficient oxygen supply and difficulty in activation during the reaction, thus reducing charge and discharge efficiency; excessive adsorption makes oxygen desorption difficult during the ORR (oxygen reduction reaction), clogging active sites and also affecting reaction efficiency.

[0010] Compared to conventional alloy catalytic systems, such as Pt / C / RuO2 catalysts, FeCoNiCu quaternary alloy catalysts, and Ni-Mn3O4 / N-rGO catalysts, which suffer from low catalytic efficiency and rapid deactivation that severely impacts battery performance, and the technical drawbacks of high-entropy alloy catalysts like FeCoNiCu which typically use heavy metals that pose serious health risks and severely limit their application scenarios, this invention relates to a non-photothermal catalytic zinc-air battery system, which is a non-toxic metal catalyst system. This solves the technical problems of existing photothermal catalytic zinc-air battery systems, such as stringent application requirements, catalytic effects dependent on photothermal effects, and inability to be applied in flexible wearable devices.

[0011] As a preferred design, the conductive titanium sheet is a pure titanium conductive sheet; And / or, the carrier gel is a PANA–PVA–IL gel.

[0012] As a preferred design, the protective film is an ITO film with a crystal orientation of 40°.

[0013] This invention further designs a protective film on the surface of the negative electrode material and selects an ITO film with a crystal orientation of (400). Firstly, it has superior corrosion resistance and conductivity, protecting the negative electrode from corrosion without affecting its conductivity. Secondly, the directionally grown monocrystalline ITO protective film has moderate mechanical strength, better chemical stability, and stronger bending resistance, making the solid-state zinc-air battery more suitable for flexible applications. Thirdly, the ITO interface layer has excellent zinc affinity, guiding Zn²⁺ to deposit uniformly on the negative electrode surface, reducing dendrite formation and avoiding damage to the electrolyte layer's mechanical structure from dendrite growth. Furthermore, the ITO interface has better hydrophilicity than the Zn interface, enabling the construction of a stable electrolyte-Zn negative electrode contact interface, further improving battery efficiency and reducing charge / discharge voltage.

[0014] Compared to traditional polycrystalline structures, which result in rough film surfaces and prominent grain boundaries, affecting device performance and stability, and require the formation of composite films such as ultrathin MoO3 layers to homogenize the ITO surface morphology and reduce roughness, this undoubtedly increases the cost of the film. Furthermore, the conductivity of the ultrathin MoO3 layer on the ITO surface is weaker than that of the ITO material itself, reducing the conductivity of the ITO film when used as an electrode material. The ITO film with a crystal orientation of (400) designed in this invention effectively solves this technical problem.

[0015] The second objective of this invention is to provide a method for preparing a solid-state zinc-air battery as described in any of the above claims, wherein the catalyst preparation process for the catalyst cathode is as follows: (1) The first mixture was obtained by mixing graphene, iridium salt and citric acid as raw materials and then ultrasonically treating it; (2) The first mixture is heated to reduce graphene to reduced graphene oxide (rGO) and to reduce Ir 3+ Reduced to Ir, yielding the second mixture; (3) Centrifuge the second mixture, wash and dry the resulting product to obtain the Ir-rGO catalyst.

[0016] As a preferred design, in step (1), the mass ratio of graphene to iridium is 18:1 to 22:1, and the molar ratio of iridium salt to citric acid is 1:9 to 1:11; The graphene is subjected to ultrasonic treatment for 1 to 1.5 hours to exfoliate it into a single layer. And / or, in step (2), the first mixture is heated at 150~200℃ for 7~10h.

[0017] As a preferred design, the catalyst cathode is prepared by uniformly spraying the catalyst onto carbon paper under a sun lamp environment.

[0018] As a preferred design, the preparation process of the catalyst cathode is as follows: Water, isopropanol, and naphthol are mixed evenly to obtain a treatment solution; After grinding the Ir-rGO catalyst, the treatment liquid is added to it. After dissolving, the resulting catalyst solution is added to a spray gun. Under a sun lamp environment, at 70-80°C for 10-20 minutes, the catalyst solution is sprayed onto carbon paper using the spray gun.

[0019] To address the current technical shortcomings of solid-state zinc-air batteries, which require an electrolyte carrier, resulting in low ionic conductivity and significant side reactions, this invention employs a preparation method using a solar lamp-assisted spray gun. This method not only forms a uniform catalyst coating, preventing the reduction of active sites due to catalyst agglomeration and ensuring catalytic efficiency, but also allows the catalyst solvent to evaporate rapidly on the carbon paper surface, enabling the catalyst to quickly adhere to the carbon paper surface. This prevents oxygen channel blockage caused by excessive catalyst solution penetration and further increases the number of active sites exposed to the electrolyte layer, thus doubly improving catalytic efficiency.

[0020] As a preferred design, the preparation process of the carrier gel includes: Prepare a deionized PVA aqueous solution; Take the 1-ethyl-3-methylimidazolium chloride ionic liquid that has been heated and melted, add the PVA deionized aqueous solution to it, and stir until homogeneous to obtain a mixed solution of PVA and ionic liquid. Prepare a sodium hydroxide solution, add N,N'-methylenebisacrylamide to it, and after it dissolves, add an acrylic acid solution. After the reaction is complete, a neutralized monomer solution is obtained. After mixing the prepared neutralized monomer solution with potassium persulfate solution, the mixed solution of PVA and ionic liquid is added, and the mixture is stirred to obtain a gel aqueous solution. After drying the gel aqueous solution, cut it into the desired shape and soak it in an electrolyte solution for 12-24 hours.

[0021] As a preferred design, the battery negative electrode is prepared by sputtering a 50-120 nm ITO thin film onto a pretreated zinc sheet using magnetron sputtering, wherein the crystal orientation of the thin film is 40°. And / or, the magnetron sputtering parameters are: Ar volumetric flow rate of 40 sccm, O2 volumetric flow rate of 0.4 sccm, pressure of 0.8 mTorr, power of 70 W, and sputtering time of 500-1200 s.

[0022] In this invention, ITO thin films are prepared by magnetron sputtering, which has the advantages of high film quality, simple method and low cost compared with other methods. It can protect the negative electrode of the battery without reducing the conductivity of the negative electrode.

[0023] As a preferred design, the assembly process of the solid zinc-air battery is as follows: the battery negative electrode, carrier gel, conductive titanium sheet, and catalyst positive electrode are stacked in sequence, and finally the battery mold is sealed to complete the battery assembly.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. This invention constructs a three-dimensional Ir-rGO cathode catalyst, leveraging the synergistic catalytic effect of three-dimensional rGO and the rare metal Ir: rGO's unique three-dimensional porous structure creates a unique gas-liquid-solid three-phase interface, providing channels for oxygen diffusion and electrolyte wetting; rGO's high specific surface area and surface functional groups can anchor Ir nanoparticles, preventing their aggregation and exposing more uniformly dispersed Ir active sites, significantly improving adsorption capacity. Furthermore, Ir loss is a major cause of catalyst deactivation; anchoring Ir nanoparticles through Ir-C bonds restricts Ir atom migration and aggregation, extending catalyst lifetime. Additionally, the oxygen adsorption capacity can be regulated through Ir-C bonds; by controlling the d-band center of Ir through rGO, the oxygen adsorption energy can be positioned within the "optimal window" of the ORR / OER reaction (neither too strong, making intermediate product desorption difficult, nor too weak, making reaction initiation difficult).

[0025] 2. This invention uses an ITO thin film with a crystal orientation of (400) to protect the battery negative electrode, resulting in stronger corrosion resistance. Furthermore, the formed ITO interface layer exhibits excellent zinc affinity, attracting Zn. 2+ Uniform deposition on the negative electrode surface reduces the formation of surface dendrites, avoiding damage to the mechanical structure of the battery electrolyte layer caused by dendrite growth. In addition, the ITO interface has better hydrophilicity than the Zn interface, forming a good electrolyte-zinc negative electrode contact interface, improving battery efficiency and further reducing battery charge and discharge voltage.

[0026] 3. The present invention uses a solar lamp + spraying experimental method to prepare the catalyst cathode, which allows the catalyst to quickly adhere to the carbon paper, avoiding the reduction of active sites exposed to the electrolyte layer due to catalyst accumulation on the carbon paper surface and the blockage of the carbon paper ventilation pores due to untimely solvent evaporation. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 The graph shows the charge and discharge test results of the solid zinc-air battery obtained in Example 1.

[0028] Figure 2 The figure shows the charge and discharge test results of the solid zinc-air battery obtained in Comparative Example 1.

[0029] Figure 3 The graph shows the charge and discharge test results of the solid zinc-air battery obtained in Comparative Example 2.

[0030] Figure 4 The figure shows the charge and discharge test results of the solid zinc-air battery obtained in Comparative Example 3.

[0031] Figure 5 The figure shows the charge and discharge test results of the solid zinc-air battery obtained in Comparative Example 4.

[0032] Figure 6 This is a morphological diagram of the negative electrode of the battery obtained in Example 1 after charging and discharging.

[0033] Figure 7 The graph shows the charge and discharge test results of the battery obtained in Example 2. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0035] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0037] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0038] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. The process is performed sequentially. For example, the method includes steps (a) and (b), indicating that the method may include step (a) performed sequentially. (b) may also include steps (b) and (a) performed sequentially. For example, the method may also include step (c). This indicates that step (c) can be added to the method in any order; for example, the method may include steps (a), (b), and (c). It may also include steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0039] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included. Example 1:

[0040] A solid-state zinc-air battery, the preparation method of which includes the following steps: 1. Preparation of cathode catalyst: (1) Weigh 190mg GO (graphene oxide), 15.5mg IrCl3, 96mg citric acid and 24ml benzyl alcohol into a sealed peeling container, sonicate for 1 hour to fully peel GO into a monolayer, and dissolve IrCl3 and citric acid evenly to obtain the first mixture.

[0041] (2) After the ultrasound is completed, heat in an oil bath at 170℃ for 8 hours to fully reduce GO to rGO to improve conductivity and make Ir 3+ Fully reduce to Ir, avoiding residual Ir 3+ This affects the catalytic activity, resulting in a second mixture.

[0042] (3) Set the rotation speed to 9000 rpm, centrifuge the second mixture for 10 minutes, and collect the product.

[0043] (4) Wash the product four times with a mixture of ethanol and acetone to remove residual reactants, and then allow it to dry naturally to obtain the Ir-rGO catalyst.

[0044] 2. Preparation of the catalyst cathode: (1) Cut the prepared carbon paper into 2cm×2cm sizes for later use.

[0045] (2) Use a pipette to take 800ml of deionized water, 200ml of isopropanol and 50ul of naphthol into a sealed peeling container, and sonicate for 30 minutes to mix and dissolve them thoroughly. This is the treatment solution.

[0046] (3) Take out the prepared Ir-rGO catalyst nanosheets, grind them into fine particles using a grinding tool, and weigh 1 mg of catalyst particles into a sealed stripping container. Add the treatment solution prepared in step (2) into the stripping container containing the fine catalyst particles, and sonicate for one hour until the catalyst and solvent are fully mixed and dissolved. At this time, the catalyst is close to the state of ink.

[0047] (4) Add the above ink-like catalyst solution to a small spray gun, and spray the catalyst solution evenly on the gray surface of the carbon paper under the sun lamp environment (temperature is 70°C) for 10 minutes to avoid gas exchange between the battery and the outside world due to catalyst agglomeration.

[0048] 3. Preparation of carrier gel (1) Prepare a PVA deionized water solution at 1g / 20ml and magnetically stir at 90℃ for 2h to form a uniform PVA solution.

[0049] (2) Take 1g of the heated and melted plasma liquid (1-ethyl-3-methylimidazolium chloride) and add it to the above PVA solution, and continue stirring for 1h to obtain a mixed solution of PVA and ionic liquid.

[0050] (3) Weigh 3.696 g of sodium hydroxide into a beaker and add 12 ml of deionized water. After it is completely dissolved, add 0.02 g of N,N'-methylenebisacrylamide (MBA, 99%) to the sodium hydroxide solution. After the mixed solution of sodium hydroxide and MBA is cooled, add 10.08 g of acrylic acid solution (AA, 99%) in a fume hood at a molar mass ratio of 2:3 for sodium hydroxide and acrylic acid. After the reaction is complete, the neutralized monomer solution is obtained.

[0051] (4) Cool the above-mentioned PVA and ionic liquid mixture to 50°C (stirring should not be stopped during the cooling process). When the temperature drops to 50°C, add the prepared neutralized monomer solution and potassium persulfate solution, and stir continuously for 30 minutes to form a gel aqueous solution.

[0052] (5) Pour the reaction mixture into a clean stripping container and dry it at 75°C for 4 hours.

[0053] (6) Cut the obtained product into the required shape, and then soak it in the electrolyte solution for 12 hours for battery fabrication. The resulting carrier gel is PANA–PVA–IL gel.

[0054] 4. Preparation of the battery negative electrode (1) Select a zinc sheet with a thickness of 2mm and cut it into 2cm×5cm size. Soak the zinc sheet in 8% dilute hydrochloric acid solution for five minutes to remove the zinc oxide layer on the surface to ensure better conductivity. After completion, use deionized water and alcohol to sonicate for 5 minutes to remove residual hydrochloric acid.

[0055] (2) After removing the surface oxide layer, use high-grit sandpaper to polish the zinc sheet to make its surface smooth. After completion, use deionized water and alcohol to ultrasonically clean it for 5 minutes.

[0056] (3) Adjust the magnetron sputtering parameters and sputter an 80nm thick ITO thin film onto the surface of the treated zinc sheet, wherein the ITO crystal orientation is (400), and the magnetron sputtering parameters are: Ar=40 sccm, O2=0.4 sccm, P=0.8mTorr, sputtering power=70w, sputtering time=500s.

[0057] 5. Battery assembly The battery assembly is completed by stacking the negative electrode, carrier gel, pure titanium conductive sheet, and catalyst positive electrode in sequence, and finally sealing the battery mold. It should be noted that the conductive titanium sheet must not block the air window of the battery.

[0058] The carbon paper used in this embodiment is CeTech GDL340, produced by a carbon energy manufacturer; the pure titanium conductive sheet is purchased from BaoTi Group; and the graphene oxide (GO) is purchased from Kaisa (Guangdong) New Materials Co., Ltd. (Guangdong, China).

[0059] The battery prepared in Example 1 was subjected to charge-discharge tests under constant current conditions of 2 mA. The results are shown below. Figure 1 As shown in the image.

[0060] Comparative Example 1: The difference from Example 1 is that the catalyst at the positive electrode was directly replaced with Pt / C / RuO2. The process for preparing the positive electrode is the same as in Example 1, using a sun lamp-assisted spray gun method, and the amount of Pt / RuO2 used is 1 mg. All other processes are also the same as in Example 1. Both Pt / C and RuO2 are commercially available. RuO2 was purchased from Bide Pharmatech, and the Pt / C catalyst was purchased from Maclean's.

[0061] Battery performance was tested using the same method as in Example 1, and the results are shown below. Figure 2 As shown in the image.

[0062] Comparative Example 2: The difference from Example 1 is that the catalyst at the positive electrode is directly replaced with a FeCoNiCu high-entropy alloy, and the amount of FeCoNiCu used is 1 mg. The rest of the process is the same as in Example 1.

[0063] The synthesis process of the FeCoNiCu high-entropy alloy catalyst is as follows: First, commercial carbon nanotubes (CNTs) were dispersed in anhydrous ethanol and sonicated in an ice-water bath for 2-3 hours to obtain a uniform dispersion.

[0064] Subsequently, the stoichiometric ratio of metal salt precursors—ferric chloride, cobalt chloride, nickel chloride, and copper chloride—was 1:0.8:0.8:1.2, dissolved in anhydrous ethanol and ultrasonically mixed at low temperature for 30-40 minutes to allow the metal ions to be fully adsorbed onto the CNT surface. The mixture was then vacuum dried at 65-75°C for 1-1.5 hours to remove solvent and low-boiling-point impurities.

[0065] Next, wet grinding was performed in a mortar for 30-60 minutes to further promote the uniform distribution and close contact of the metal salt on the CNT surface. Afterwards, the mixture was dried in a vacuum oven at 65-75°C for 24-26 hours to obtain the precursor powder. Finally, an appropriate amount of the precursor powder was filled into a graphite mold and placed in a Joule heating device. Under an argon atmosphere, the temperature was rapidly raised to 2200-2300°C within 2 ms and held for 5 seconds; the product was then immediately immersed in liquid nitrogen (–196°C) for quenching. Through multiple cycles of synthesis and subsequent gentle grinding, the FeCoNiCu composite material was finally obtained.

[0066] Battery performance was tested using the same method as in Example 1, and the results are shown below. Figure 3 As shown in the image.

[0067] Depend on Figures 1-3 It is evident that the positive electrode catalyst in this invention is Ir-rGO, resulting in a battery with better charge-discharge performance, achieving a long cycle life of over 600 cycles. During constant current charge-discharge, the voltage change is stable, without voltage spikes or drops, demonstrating stable performance. This indicates that the battery catalyst obtained in Example 1 exhibits excellent bipolar catalytic activity, maintaining activity for extended periods and continuously catalyzing the reaction, while suppressing side reactions and preventing battery failure due to the rapid accumulation of side reaction residues.

[0068] In Comparative Example 1, replacing the cathode catalyst with Pt / C / RuO2 significantly reduced the charge-discharge cycle time. In Comparative Example 2, replacing the cathode catalyst with a FeCoNiCu high-entropy alloy also resulted in a noticeable decrease in charge-discharge cycle time, and the catalyst effect was unstable, leading to a continuous increase in battery charging voltage.

[0069] Comparative Example 3: The difference from Example 1 is that when preparing the battery negative electrode, the protective film is replaced with AlN with a thickness of 80nm, and magnetron sputtering is used. The magnetron sputtering parameters are: Ar=40 sccm, N2=15 sccm, P=2.5mTorr, sputtering power=70w, and sputtering time=1000s.

[0070] Battery performance was tested using the same method as in Example 1, and the results are shown below. Figure 4 As shown in the image.

[0071] Comparative Example 4: The difference from Example 1 is that when preparing the battery negative electrode, the protective film is replaced with ZnO with a thickness of 80nm, and magnetron sputtering is used. The magnetron sputtering parameters are: Ar=40 sccm, O2=0.4 sccm, P=0.8mTorr, sputtering power=70w, and sputtering time=400s.

[0072] Battery performance was tested using the same method as in Example 1, and the results are shown below. Figure 5 As shown in the image.

[0073] Depend on Figure 1 , 4 As shown in Figure 5, when the protective film on the negative electrode of the battery is replaced, such as with AlN or ZnO films, the performance of the resulting battery is significantly worse than that of Example 1. This indicates that other film materials such as AlN and ZnO cannot provide more effective protection for the negative electrode of the battery, proving the necessity of using ITO film in this invention. Figure 6 The image also shows the morphology of the negative electrode of the battery obtained in the embodiment after 600 cycles of continuous charge and discharge. The negative electrode of the battery remains in good condition and has not been corroded. Example 2:

[0074] A solid-state zinc-air battery, the preparation method of which includes the following steps: 1. Preparation of cathode catalyst: (1) Weigh 200 mg GO (graphene oxide), 18.0 mg Ir(NO3)3, 96 mg citric acid and 30 ml benzyl alcohol into a sealed peeling container, sonicate for 1.5 hours to fully peel GO into a monolayer, and dissolve IrCl3 and citric acid evenly to obtain the first mixture.

[0075] (2) After the ultrasound is completed, heat in an oil bath at 200℃ for 7 hours to fully reduce GO to rGO to improve conductivity and make Ir 3+ Fully reduce to Ir, avoiding residual Ir 3+ This affects the catalytic activity, resulting in a second mixture.

[0076] (3) Set the rotation speed to 10000 rpm, centrifuge the second mixture for 10 minutes, and collect the product.

[0077] (4) Wash the product four times with a mixture of ethanol and acetone to remove residual reactants, and then allow it to dry naturally to obtain the Ir-rGO catalyst.

[0078] 2. Preparation of the catalyst cathode: (1) Cut the prepared carbon paper into 2cm×2cm sizes for later use.

[0079] (2) Use a pipette to take 800ml of deionized water, 200ml of isopropanol and 100ul of naphthol into a sealed peeling container, and sonicate for 45 minutes to mix and dissolve them thoroughly. This is the treatment solution.

[0080] (3) Take out the prepared Ir-rGO catalyst nanosheets, grind them into fine particles using a grinding tool, and weigh 3.5 mg of catalyst particles into a sealed stripping container. Add the treatment solution prepared in step (2) into the stripping container containing the fine catalyst particles, and sonicate for one hour until the catalyst and solvent are fully mixed and dissolved. At this time, the catalyst is close to the state of ink.

[0081] (4) Add the above ink-like catalyst solution to a small spray gun, and spray the catalyst solution evenly onto the gray surface of the carbon paper under a sun lamp environment (temperature is 80°C) for 10 minutes to avoid gas exchange between the battery and the outside world due to catalyst agglomeration.

[0082] 3. Preparation of carrier gel (1) Prepare a PVA deionized water solution at 1.2 g / 20 ml and stir magnetically at 90 °C for 2-3 h to form a homogeneous PVA solution.

[0083] (2) Take 1.5g of the ionic liquid (1-ethyl-3-methylimidazolium chloride) that has been heated and melted and add it to the above PVA solution, and continue stirring for 2h to obtain a mixed solution of PVA and ionic liquid.

[0084] (3) Weigh 3.696 g of sodium hydroxide into a beaker and add 15 ml of deionized water. After it is completely dissolved, add 0.02 g of N,N'-methylenebisacrylamide (MBA, 99%) to the sodium hydroxide solution. After the mixed solution of sodium hydroxide and MBA is cooled, add 10.08 g of acrylic acid solution (AA, 99%) in a fume hood at a molar mass ratio of 2:3 for sodium hydroxide and acrylic acid. After the reaction is complete, the neutralized monomer solution is obtained.

[0085] (4) Cool the above-mentioned PVA and ionic liquid mixture to 60°C (stirring should not be stopped during the cooling process). When the temperature drops to 60°C, add the prepared neutralized monomer solution and potassium persulfate solution, and stir continuously for 30 minutes to form a gel aqueous solution.

[0086] (5) Pour the reaction mixture into a clean stripping container and keep it dry at 65°C for 3 minutes.

[0087] (6) Cut the obtained product into the required shape, and then soak it in the electrolyte solution for 24 hours for battery manufacturing. The resulting carrier gel is PANA–PVA–IL gel.

[0088] 4. Preparation of the battery negative electrode (1) Select a zinc sheet with a thickness of 2mm and cut it into 2cm×5cm sizes. Soak the zinc sheet in an 8% dilute hydrochloric acid solution for five minutes to remove the zinc oxide layer on the surface to ensure better conductivity. After completion, use deionized water and alcohol to sonicate for 8 minutes to remove residual hydrochloric acid.

[0089] (2) After removing the surface oxide layer, use high-grit sandpaper to polish the zinc sheet to make its surface smooth. After completion, use deionized water and alcohol to ultrasonically clean it for 5 minutes.

[0090] (3) Adjust the magnetron sputtering parameters and sputter an 80nm thick ITO thin film onto the surface of the treated zinc sheet, wherein the ITO crystal orientation is (400), and the magnetron sputtering parameters are: Ar=40 sccm, O2=0.4 sccm, P=0.8mTorr, sputtering power=70w, sputtering time=500s.

[0091] 5. Battery assembly The battery assembly is completed by stacking the negative electrode, carrier gel, pure titanium conductive sheet, and catalyst positive electrode in sequence, and finally sealing the battery mold. It should be noted that the conductive titanium sheet must not block the air window of the battery.

[0092] The battery prepared in Example 2 was subjected to charge-discharge tests under constant current conditions of 2 mA. The results are shown below. Figure 7 As shown in the figure, the obtained battery has good charge and discharge performance.

[0093] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., 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 solid-state zinc-air battery, characterized by, The battery includes a catalyst positive electrode, a conductive titanium sheet, a carrier gel, and a battery negative electrode, wherein the catalyst of the catalyst positive electrode is a metal iridium dispersed on the surface of reduced graphene oxide; The battery negative electrode has a protective film with a thickness of 50-120 nm on the surface.

2. The solid-state zinc-air battery of claim 1, wherein, The conductive titanium sheet is a pure titanium conductive titanium sheet. The carrier gel is a PANA-PVA-IL gel.

3. The solid-state zinc-air battery of claim 1, wherein, The protective film is an ITO film, and the crystal direction of the ITO film is 400.

4. The method of any one of claims 1-3, wherein the method further comprises: The preparation process of the catalyst of the catalyst positive electrode is as follows: (1) mixing graphene, iridium salt, and citric acid, and then ultrasonic treatment to obtain a first mixed solution; (2) heating the first mixture to reduce the graphene to reduced graphene oxide rGO and to reduce the Ir 3+ to Ir to obtain a second mixture; (3) centrifugal separation of the second mixed solution, and washing and drying the obtained product to obtain an Ir-rGO catalyst.

5. The preparation method according to claim 4, characterized in that, In step (1), the mass ratio of graphene to iridium is 18:1-22:1, and the molar ratio of iridium salt to citric acid is 1:9-1:11; Ultrasonic treatment for 1-1.5 h to exfoliate the graphene into single layers; In step (2), the first mixed solution is heated at 150-200°C for 7-10 h.

6. The preparation method according to claim 4, characterized in that, The preparation process of the catalyst positive electrode is to uniformly spray the catalyst on carbon paper in a solar lamp environment.

7. The production method according to claim 6, wherein The preparation process of the catalyst positive electrode is as follows: Mix water, isopropyl alcohol, and naphthol to obtain a treatment solution; Grind the Ir-rGO catalyst, add the treatment solution to the Ir-rGO catalyst, dissolve the catalyst solution, and then spray the catalyst solution on carbon paper using a spray gun in a solar lamp environment at 70-80°C for 10-20 minutes.

8. The preparation method according to claim 4, characterized in that, The preparation process of the carrier gel includes: Prepare a PVA deionized water solution; Take the heated and melted 1-ethyl-3-methylimidazolium chloride ionic liquid, add the PVA deionized water solution to the ionic liquid, and stir until uniform to obtain a mixed solution of PVA and ionic liquid; A sodium hydroxide solution was prepared and N, N ， - methylene bisacrylamide, after dissolution, add acrylic acid solution, after the reaction is complete, get neutralized monomer solution; Mix the prepared neutralized monomer solution and potassium persulfate solution, add the mixed solution of PVA and ionic liquid, stir, and obtain a gel aqueous solution; Dry the gel aqueous solution, cut it into the desired shape, and soak it in an electrolyte solution for 12-24 hours.

9. The preparation method according to claim 4, characterized in that, The preparation process of the battery negative electrode is to sputter an ITO film with a thickness of 50-120 nm on a pretreated zinc sheet using a magnetron sputtering method, and the crystal direction of the film is 400; The magnetron sputtering parameters are as follows: Ar volume flow rate is 40 sccm, O2 volume flow rate is 0.4 sccm, pressure is 0.8 mTorr, power is 70 w, and sputtering time is 500-1200 s.

10. The method of claim 4, wherein, The assembly process of the solid-state zinc air battery is as follows: stack the battery negative electrode, the carrier gel, the conductive titanium sheet, and the catalyst positive electrode in sequence, and finally seal the battery mold to complete the battery assembly.

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