Zinc air battery electrode material and preparation method thereof
Sulfur-doped porous carbon nanomaterials were prepared by solvothermal reaction and thermochemical treatment, which solved the problem of slow oxygen reduction reaction kinetics in zinc-air batteries, achieving high-efficiency oxygen reduction performance and improved battery energy density, with good stability and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-03-27
AI Technical Summary
The oxygen reduction reaction kinetics in zinc-air batteries are slow, existing platinum-based catalysts are expensive and rare, and the problem of preparing high-content active sites in sulfur-doped carbon nanomaterials has not been effectively solved.
Sulfur-doped porous organic polymers were constructed through solvothermal reactions and then subjected to thermochemical treatment at high temperatures to form stable carbon-sulfur bonds, providing abundant reaction sites for the preparation of zinc-air battery electrode materials.
It improves the oxygen reduction reaction activity and kinetic rate of zinc-air batteries, enhances battery energy density and stability, reduces costs, and exhibits good cycle stability and safety.
Smart Images
Figure CN121748415A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of zinc-air battery electrode materials, and particularly relates to a zinc-air battery electrode material and a preparation method thereof. BACKGROUND
[0002] In recent years, with the increasing depletion of fossil fuels and the aggravation of environmental pollution problems, it has become an urgent task to find renewable and clean energy. Under this background, zinc-air batteries (ZABs) have gradually attracted widespread attention in the field of energy and environmental sustainability due to their high energy density and good environmental compatibility. However, the application of zinc-air batteries is challenged by the slow kinetics of the oxygen reduction reaction (ORR), which seriously hinders its widespread application. Currently, platinum-based materials are considered to be the most effective ORR catalysts, but their high cost and rarity limit their large-scale application in ZABs.
[0003] In recent years, metal-free functional carbon materials have become a research hotspot due to their chemical stability, low cost and high catalytic activity. Generally, the introduction of heteroatoms into the carbon skeleton can significantly improve the catalytic performance of ORR. Although current researches mainly focus on nitrogen-doped carbon nanomaterials, there is still controversy about their specific active sites. It is worth noting that sulfur-doped carbon nanomaterials show good potential in improving the activity of ORR. Studies have shown through density functional theory calculations that sulfur doping can effectively reduce the energy barrier of O2 forming *OOH, thereby enhancing the intrinsic activity of sulfur. More importantly, studies have shown that sulfur can be doped into carbon materials in the form of sulfides and sulfonates, and ultimately act as the main active site through C-S bond configuration to participate in the ORR process. In addition, studies have also demonstrated that the five-membered ring thiophene-sulfur structure can act as an active center to promote the catalytic reaction of ORR. Therefore, one of the significant advantages of sulfur-doped carbon nanomaterials is that they have a clear active site C-S, which lays the foundation for further research on other influencing factors of sulfur-doped carbon materials. However, so far, how to prepare high content of active site C-S through an effective reaction route remains a challenging task. SUMMARY
[0004] The purpose of the present application is to provide a zinc-air battery electrode material and a preparation method thereof, which enables high content of carbon-sulfur bonds in sulfur-doped carbon nanomaterials, and these carbon-sulfur bonds can provide more reaction active sites and stable chemical structures, thereby increasing the activity of the cathode oxygen reduction reaction of zinc-air batteries and improving the reaction kinetics rate of the reaction, ultimately greatly improving the energy density and stability of zinc-air batteries.
[0005] To solve the above problems, the present application adopts the following technical solutions:
[0006] A zinc-air battery electrode material, the preparation method of which includes the following steps:
[0007] (a) Thiophene monomer is dissolved in a solvent, a catalyst is added and mixed evenly, and polymerization is carried out at -10~120 °C to obtain a sparingly soluble product;
[0008] (b) Wash the insoluble material with dilute acid and deionized water, and dry it to obtain porous organic polymer powder;
[0009] (c) The porous organic polymer powder is heated to 250~1600 °C under an inert atmosphere to obtain zinc-air battery electrode material after reaction.
[0010] Preferably, the catalyst is anhydrous aluminum chloride, anhydrous ferric chloride, or potassium persulfate, and the molar ratio of thiophene to the catalyst is 1:1 to 10.
[0011] Preferably, the solvent is 1,2-dichloroethane, nitrobenzene, or chloroform, and the molar ratio of thiophene to the solvent is 1:1 to 100.
[0012] Preferably, in step (a), the polymerization reaction is carried out at 0~120 °C; in step (c), the temperature is heated to 400~900 °C in an inert atmosphere.
[0013] Preferably, (a) the thiophene monomer is dissolved in a solvent, the catalyst is added, the reactants are thoroughly mixed in an ice-water bath, and then the temperature is raised to 45~120 °C to react and obtain the precipitate; (b) the precipitate is thoroughly washed with dilute hydrochloric acid / deionized water in a Soxhlet extractor and dried to obtain the porous organic polymer powder; (c) the porous organic polymer powder is heated to 800 °C at a controlled heating rate of 3 °C / min under an inert atmosphere and reacted to obtain the zinc-air battery electrode material.
[0014] Another object of the present invention is to provide a zinc-air battery electrode material prepared by the above method.
[0015] This invention employs a solvothermal reaction to construct a sulfur-doped porous organic polymer, followed by thermochemical treatment to obtain sulfur-doped porous carbon nanomaterials. During the thermochemical reaction, sulfur free radicals generated at high temperatures bond with the carbon framework, stabilizing the material system in a covalent manner and preserving the carbon-sulfur bonds. These carbon-sulfur bonds within the carbon framework provide abundant reaction sites during the oxygen reduction reaction at the cathode of a zinc-air battery, ultimately improving the battery's specific capacity and energy density. Simultaneously, it exhibits good cycle stability and reaction kinetics, and contributes to enhancing the safety of the electrode material. The raw materials used are widely available and stable, the reaction conditions are easily controlled, the raw materials have low toxicity, and the process is low-risk. Attached Figure Description
[0016] Figure 1 Here are scanning electron microscope images of the electrode material obtained in Example 1;
[0017] Figure 2 Transmission electron microscope image of the electrode material obtained in Example 1;
[0018] Figure 3 The infrared spectra of the electrode material and its precursor obtained in Example 1 are shown below.
[0019] Figure 4 The X-ray photoelectron spectrum of the electrode material obtained in Example 1 is shown below.
[0020] Figure 5 The cyclic voltammetry curves are based on the oxygen reduction reaction catalyzed by the electrode material obtained in Example 1.
[0021] Figure 6 Linear sweep voltammetry curves of oxygen reduction reaction catalyzed by the electrode material obtained in Example 1;
[0022] Figure 7 The open-circuit voltage test curve of the zinc-air battery assembled based on the electrode material obtained in Example 1;
[0023] Figure 8 The discharge curve of the zinc-air battery assembled based on the electrode material obtained in Example 1;
[0024] Figure 9 The rate performance curve of the zinc-air battery assembled based on the electrode material obtained in Example 1;
[0025] Figure 10 The discharge polarization curves are for the zinc-air battery assembled based on the electrode materials obtained in Example 1.
[0026] Figure 11 The X-ray photoelectron spectrum of the electrode material obtained in Example 2;
[0027] Figure 12 The cyclic voltammetry curves are based on the oxygen reduction reaction catalyzed by the electrode material obtained in Example 2. Detailed Implementation
[0028] The present invention will be further described below through specific embodiments.
[0029] Example 1
[0030] 0.02 mol (1890 μL) of thiophene monomer was dissolved in 120 mL of nitrobenzene, and 8.58 g of anhydrous ferric chloride catalyst was added. The mixture was heated to 120 °C for 24 hours under magnetic stirring to obtain a brown, sparingly soluble substance. After washing with 2 M hydrochloric acid solution and deionized water for 12 hours in a Soxhlet extractor, the sparingly soluble substance was dried to obtain a porous organic polymer powder. Subsequently, the obtained polymer was heated to 800 °C at a controlled heating rate of 3 °C / min under an inert atmosphere (nitrogen or argon) and reacted for one hour to obtain sulfur-doped porous carbon nanomaterials containing carbon-sulfur covalent bonds, i.e., zinc-air battery electrode materials.
[0031] Example 2
[0032] 0.01 mol (945 μL) of thiophene monomer was dissolved in 20 mL of 1,2-dichloroethane. 1.60 g of anhydrous ferric chloride catalyst and 3600 μL of dimethoxymethane were added. The reactants were mixed uniformly at 0 °C for 10 minutes, then the temperature was increased to 45 °C and reacted for 5 hours. The temperature was then further increased to 80 °C and reacted for 19 hours to obtain a sparingly soluble compound. The precipitate was thoroughly washed with dilute hydrochloric acid / deionized water in a Soxhlet extractor for 24 hours, and then the product was dried to obtain a porous organic polymer powder. Subsequently, the obtained polymer was reacted at an inert atmosphere (argon or nitrogen) with a controlled heating rate of 3 °C / min to 800 °C for 0.5 hours to obtain sulfur-doped porous carbon nanomaterials rich in carbon-sulfur bonds, i.e., zinc-air battery electrode materials.
[0033] Example 3
[0034] 0.01 mol (945 μL) of thiophene monomer was dissolved in 120 mL of 1 M hydrochloric acid solution, and 5.41 g of potassium persulfate catalyst was added. After stirring at room temperature for 10 minutes, the mixture was heated to 60 °C and reacted for 72 hours to obtain a sparingly soluble substance. The precipitate was thoroughly washed with dilute hydrochloric acid / deionized water in a Soxhlet extractor for 24 hours, and the product was dried to obtain a porous organic polymer powder. Subsequently, the obtained polymer was heated to 800 °C at a controlled heating rate of 3 °C / min under an inert atmosphere (argon or nitrogen) and reacted for 0.5 hours to obtain sulfur-doped porous carbon nanomaterials rich in carbon-sulfur bonds, i.e., zinc-air battery electrode materials.
[0035] Example 4
[0036] 0.01 mol (945 μL) of thiophene monomer was dissolved in 20 mL of 1,2-dichloroethane. 1.30 g of anhydrous aluminum chloride catalyst and 3600 μL of dimethoxymethane were added. The reactants were mixed uniformly at 0 °C for 10 minutes, then the temperature was increased to 45 °C and reacted for 5 hours. The temperature was then further increased to 70 °C and reacted for 19 hours to obtain a sparingly soluble compound. The precipitate was thoroughly washed with dilute hydrochloric acid / deionized water in a Soxhlet extractor for 24 hours, and then the product was dried to obtain a porous organic polymer powder. Subsequently, the obtained polymer was reacted at an inert atmosphere (argon or nitrogen) with a controlled heating rate of 3 °C / min to 800 °C for 0.5 hours to obtain sulfur-doped porous carbon nanomaterials rich in carbon-sulfur bonds, i.e., zinc-air battery electrode materials.
[0037] Example 5
[0038] 0.02 mol (1890 μL) of thiophene monomer was dissolved in 120 mL of nitrobenzene, and 7.63 g of anhydrous ferric chloride catalyst was added. The mixture was heated to 120 °C for 24 hours under magnetic stirring to obtain a brown, insoluble substance. After washing with 2 M hydrochloric acid solution and deionized water for 12 hours in a Soxhlet extractor, the insoluble substance was dried to obtain a porous organic polymer powder. Subsequently, the obtained polymer was heated to 600 °C at a controlled heating rate of 3 °C / min under an inert atmosphere (nitrogen or argon) and reacted for one hour to obtain sulfur-doped porous carbon nanomaterials containing carbon-sulfur covalent bonds, i.e., zinc-air battery electrode materials.
[0039] Example 6
[0040] 0.01 mol (945 μL) of thiophene monomer was dissolved in 120 mL of 1 M hydrochloric acid solution, and 5.41 g of potassium persulfate catalyst was added. After stirring at room temperature for 10 minutes, the mixture was heated to 60 °C and reacted for 72 hours to obtain a sparingly soluble substance. The precipitate was thoroughly washed with dilute hydrochloric acid / deionized water in a Soxhlet extractor for 24 hours, and the product was dried to obtain a porous organic polymer powder. Subsequently, the obtained polymer was heated to 400 °C at a controlled heating rate of 3 °C / min under an inert atmosphere (argon or nitrogen) and reacted for 0.5 hours to obtain sulfur-doped porous carbon nanomaterials rich in carbon-sulfur bonds, i.e., zinc-air battery electrode materials.
[0041] Example 7 Characterization and Performance Testing
[0042] Scanning electron microscope (SEM) images of the zinc-air battery electrode material prepared in Example 1 are shown below. Figure 1 As shown, the transmission electron microscope image of this material is as follows: Figure 2 As shown, the lens image and scanning electron microscope (SEM) image demonstrate that this electrode material possesses a cross-linked cluster structure, which is beneficial for exhibiting excellent catalytic performance in subsequent electrocatalytic processes. The infrared spectrum of this material is as follows: Figure 3 As shown, in the range of 780~600 cm-1 CS bonds were present throughout the range, indicating the successful preparation of the sulfur-doped carbon material. The X-ray photoelectron spectrum of this material is shown in the figure below. Figure 4 As shown, by analyzing the X-ray photoelectron spectrum of sulfur and performing peak segmentation, it can be seen that the obtained electrode material is rich in carbon-sulfur bonds, which are beneficial for participating in the electrocatalytic reaction process as active sites.
[0043] The X-ray photoelectron spectrum of the electrode material prepared in Example 2 is as follows: Figure 11 As shown, the electrode material synthesized using dichloroethane as a solvent also contains carbon-sulfur bonds that are beneficial for improving electrocatalytic performance. Other embodiments also exhibit similar characteristics.
[0044] The performance of the zinc-air battery electrode material obtained in Example 1 was tested. A 6 M potassium hydroxide and 0.2 M zinc acetate solution was used as the electrolyte, Nafion (5% by mass) as the binder, a polished zinc sheet as the anode, and carbon paper loaded with a catalyst as the cathode. Performance testing methods included cyclic voltammetry, constant current charge-discharge method, linear sweep voltammetry, and charge-discharge rate performance testing at different current densities.
[0045] Figure 5 Cyclic voltammetry curves of the electrode material catalyzing the oxygen reduction reaction, obtained in Example 1, are used to study the electrochemical behavior of the electrode material within the test voltage range. Cyclic voltammetry tests demonstrate that the material exhibits an oxygen reduction peak at approximately 0.83 V during charge-discharge processes, indicating that the material possesses excellent catalytic ability for the oxygen reduction reaction. Figure 12 The cyclic voltammetry curves are for the sodium-ion battery assembled using the thiophene monomer-based negative electrode material in Example 2, and are similar to those in Example 1. Figure 12 This is a cyclic voltammetry test of the oxygen reduction reaction catalyzed by the electrode material prepared in Example 2 using dichloroethane as a solvent, compared to... Figure 5 The cyclic voltammetry curves of the electrode material obtained in Example 1 for the oxygen reduction reaction show that the reduction potential of Example 1 is higher, indicating that the electrode material obtained using nitrobenzene as a solvent has superior oxygen reduction reaction performance. Based on the similarity between Examples 1 and 2, it can be inferred that the electrocatalytic oxygen reduction reaction performance of the material prepared in this invention is mainly based on the carbon-sulfur bonds formed by sulfur heteroatoms on the parent ring during the reaction. Example 3, using potassium persulfate as a catalyst, also exhibits similar performance.
[0046] Figure 6 This is a linear sweep voltammetry curve of the oxygen reduction reaction catalyzed by the electrode material of Example 1. Its half-wave potential and kinetic limiting current density reach 0.826 V and 163.87 mA cm⁻¹, respectively. -2This result is far superior to the findings reported in the literature. In practical applications, this property helps to enhance the activity and accelerate the kinetics of the oxygen reduction reaction.
[0047] Figure 7 The open-circuit voltage test curve of the zinc-air battery assembled with the electrode material obtained in Example 1 shows that it still maintains the initial voltage value after 400 test cycles, indicating that the battery has excellent stability and low self-discharge rate.
[0048] Figure 8 The discharge curve of the zinc-air battery assembled with the obtained electrode material is shown at 5 mA cm⁻¹. -2 At a current density, it showed 746 mAh g. -1 High discharge capacity.
[0049] Figure 9 This is a rate performance graph of a zinc-air battery assembled with the electrode materials obtained in Example 1. It can achieve a rate of 5 mA cm⁻¹. -2 The voltage was maintained at 1.13 V during testing, followed by 0.5 mA cm⁻¹. -2 The voltage returned to the initial 1.21 V at the current density, indicating that the zinc-air battery has excellent stability.
[0050] Figure 10 The electrode material obtained in Example 1 is used in a zinc-air battery, and its discharge polarization curve shows that the peak power density of the zinc-air battery reaches 121.1 mW / cm². -2 This is significantly higher than the power density of zinc-air batteries using most currently reported sulfur-doped carbon electrode materials.
[0051] The above embodiments are merely illustrative of the concept and implementation of the present invention and are not intended to limit it. Under the concept of the present invention, technical solutions without substantial changes are still within the scope of protection.
Claims
1. A zinc-air battery electrode material, characterized in that... Includes the following steps: (a) Thiophene monomer is dissolved in a solvent, a catalyst is added, and polymerization is carried out at -10 to 180 °C to obtain a sparingly soluble product; (b) The insoluble material was thoroughly washed with an acidic solution and deionized water, and then dried to obtain porous organic polymer powder; (c) The above porous organic polymer powder is heated to 250~1600 °C in an inert atmosphere and after heat treatment reaction, zinc-air battery electrode material is obtained.
2. The preparation method according to claim 1, characterized in that, The catalyst is ferric chloride, aluminum chloride, or potassium persulfate; the solvent is 1,2-dichloroethane, nitrobenzene, or hydrochloric acid solution; the molar ratio of the thiophene monomer to the catalyst is 1:1 to 10; and the molar ratio of the thiophene monomer to the solvent is 1:1 to 100.
3. The preparation method according to claim 1, characterized in that, In step (a), the polymerization reaction is carried out at 0~120 °C; in step (c), the heat treatment process is carried out in an inert atmosphere and heated to 400~900 °C.
4. The preparation method according to claim 1, characterized in that, (a) The thiophene monomer is dissolved in a solvent, the catalyst is added, the reactants are mixed under low temperature conditions, and then the temperature is raised to 45~120 °C to react, thereby obtaining the sparingly soluble substance; (b) The sparingly soluble substance is washed with deionized water under acidic conditions and dried to obtain the porous organic polymer powder; (c) The porous organic polymer powder is heated to 800 °C at a heating rate of 2~4 °C per minute and reacted to obtain the zinc-air battery electrode material.
5. A zinc-air battery electrode material, characterized in that... Prepared by the preparation method according to any one of claims 1 to 4.