Preparation method and application of FeCo2O4 / PANI composite material
By preparing porous FeCo2O4 nanoparticles and compounding them with polyaniline, the FeCo2O4/PANI composite material was solved, and the electrochemical performance of the supercapacitor was significantly improved.
Patent Information
- Application Number
- CN202510604362.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2025-07-25
AI Technical Summary
The prior art is difficult to effectively improve the specific surface area and electrochemical activity of FeCo2O4 electrode materials, limiting the performance of supercapacitors.
Porous FeCo2O4 nanoparticles were prepared by using sodium dodecylbenzenesulfonate as a template agent, and the pre-assembly of aniline on the surface of FeCo2O4 nanoparticles was controlled by calcining the residual sulfonic acid group, and combined with the polymerization of polyaniline, forming a FeCo2O4/PANI composite material.
The specific surface area and conductivity of FeCo2O4/PANI composite materials have been significantly improved, the specific capacitance and cyclic stability of supercapacitors have been enhanced, and the synergistic effect of double layer capacitors and PANI has been provided by FeCo2O4, which improves electrochemical performance.
Smart Images
Figure CN120376347A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of supercapacitors, and particularly to a preparation method and application of an FeCo2O4 / PANI composite material. Background Art
[0002] The porosity of the electrode material directly affects the electrochemical performance of the electrode. For the Faraday reaction, the larger the specific surface area, the more active sites, and the higher the ion and electron response frequency. So far, there are few reports on the preparation of FeCo2O4 with a large specific surface area, which means there is an opportunity to synthesize FeCo2O4 materials with a scaled surface area through a simple synthesis method, thereby generating excellent electrochemical activity.
[0003] For example, the invention patent application with the application number 201910324018X discloses a preparation method and application of a nano-needle-shaped FeCo2O4 electrode material. In this patent, a hydrothermal method is used to prepare the nano-needle-shaped FeCo2O4 electrode material, and by preparing a one-dimensional nano-needle structure to increase the specific surface area of the FeCo2O4 electrode material, more abundant electrochemical active sites and more Fe 2+ / Fe 3+ and Co 2+ / Co 3+ redox reaction electron pairs are provided, but the improvement effect is limited. Summary of the Invention
[0004] The purpose of the present invention is to provide a preparation method of an FeCo2O4 / PANI composite material. The present invention uses sodium dodecylbenzenesulfonate as a template agent to manufacture FeCo2O4 nanoparticles with a porous structure, and then controls the pre-assembly of aniline on the FeCo2O4 nanoparticles by cooperating with the sulfonic acid groups remaining after calcination, effectively improving the conductivity of polyaniline to FeCo2O4.
[0005] To solve this technical problem, the technical solution of the present invention is: a preparation method of an FeCo2O4 / PANI composite material, comprising the following steps: S1. Prepare FeCo2O4 nanoparticles containing sulfonic acid groups by using the sol-gel method; S2. Ultrasonically disperse the FeCo2O4 nanoparticles containing sulfonic acid groups in HCl; S3. Add aniline to the dispersion system obtained in S2, and the aniline and the sulfonic acid groups of the FeCo2O4 nanoparticles form a pre-assembly through electrostatic adsorption and hydrogen bonding; The dosage of aniline and the FeCo2O4 nanoparticles containing sulfonic acid groups is calculated according to aniline and FeCo2O4, and the molar ratio of aniline to FeCo2O4 is 1:(8 to 10).
[0006] S4. Slowly drop ammonium persulfate into the dispersion system obtained in S3 at a certain rate, controlling the polymerization of aniline pre-assembled on the surface of FeCo2O4 nanoparticles into polyaniline. At the same time, the sulfonic acid groups on the surface of FeCo2O4 nanoparticles serve as dopants and polymerization sites; S5. Wash the solid particles obtained in S4 alternately with HCl and ethanol, and dry them at low temperature to obtain the FeCo2O4 / PANI composite material.
[0007] Preferably, the preparation method of FeCo2O4 nanoparticles containing sulfonic acid groups includes the following steps: S11. Dissolve Fe(NO3)3·9H2O, Co(NO3)2·6H2O and citric acid as a chelating agent in deionized water according to the stoichiometric ratio of Fe and Co; S12. Slowly drop sodium dodecylbenzenesulfonate dispersed in water and ethanol into the mixed system obtained in S11 under stirring conditions; S13. Continuously stir in a water bath for 4 to 6 hours to form a uniform sol; S14. Heat and let stand to form a wet gel, and dry it under vacuum to obtain a dry gel; S15. Calcinate at low temperature to obtain FeCo2O4 nanoparticles with sulfonic acid groups.
[0008] Preferably, in the preparation of FeCo2O4 nanoparticles containing sulfonic acid groups, the amount of substance of the target FeCo2O4 is n1, the amount of substance of citric acid is n2, and the amount of substance of sodium dodecylbenzenesulfonate is n3. Among them, n1 and n2 and n3 respectively satisfy the following relationships: n1:n2 is 1:(1.5 to 2.0); n1:n3 is 1:(0.5 to 1).
[0009] Preferably, use ammonia water to adjust the pH of the mixed system in step S11 to 3 to 4.
[0010] Preferably, the process conditions for low-temperature calcination in S15 are: 360°C to 380°C, 2 to 3 hours in a nitrogen atmosphere.
[0011] The present invention controls the calcination temperature and atmosphere, retains an appropriate amount of sulfonic acid groups to guide the orderly growth of PANI, and at the same time avoids excessive carbon residue.
[0012] Preferably, the molar ratio of aniline to FeCo2O4 nanoparticles containing sulfonic acid groups is 1:(8 to 10). The present invention controls the polyaniline attached to the surface of porous FeCo2O4 nanoparticles, and uses sulfonic acid groups to anchor polyaniline on the surface of FeCo2O4 nanoparticles to ensure the balance between the improvement of the conductivity of PANI and the retention of pores.
[0013] Preferably, the process conditions for polymerization in step S4 are as follows: The temperature is controlled at 0 °C to 5 °C; The polymerization time is 6 h to 8 h; The stirring conditions are 150 rpm to 200 rpm.
[0014] Another object of the present invention is to provide an application of the FeCo2O4 / PANI composite material prepared by the present invention in a supercapacitor. The supercapacitor proposed by the present invention utilizes the synergistic effect of FeCo2O4 providing double-layer capacitance and PANI providing pseudocapacitance to improve the specific capacitance and cycle stability.
[0015] To solve this technical problem, the technical solution of the present invention is: The supercapacitor proposed by the present invention uses the FeCo2O4 / PANI composite material as the cathode and activated carbon as the anode to assemble a FeCo2O4 / PANI composite material / / AC hybrid supercapacitor.
[0016] Preferably, manufacturing the FeCo2O4 / PANI composite material into the cathode includes the following steps: A1. Mix FeCo2O4 / PANI, a conductive agent, and PVDF in a ratio of 0.8:0.1:0.1, add N-methylpyrrolidone (NMP) and grind into a uniform slurry, and uniformly coat the slurry on nickel foam; dry in vacuum at 80 °C for 12 hours; A2. Compress with a tablet press at a pressure of 5 to 10 MPa to obtain a cathode sheet.
[0017] Preferably, the supercapacitor uses 0.5 to 1.0 M H2SO4 as the electrolyte.
[0018] By adopting the above technical solution, the beneficial effects of the present invention are: The present invention uses FeCo2O4 as a carrier to in-situ modify and grow polyaniline on its surface to prepare a FeCo2O4 / PANI composite material. The obtained composite material forms a tight interfacial contact, improves the specific surface area, and promotes electron / ion transport; the composite material obtained by the present invention combines the high redox activity of metal oxides and the pseudocapacitance characteristics of PANI, significantly improving the specific capacity and cycle life; The present invention uses sodium dodecylbenzenesulfonate as a template agent to manufacture FeCo2O4 nanoparticles with a porous structure, and then controls the pre-assembly of aniline on the FeCo2O4 nanoparticles by the sulfonic acid groups remaining after calcination. Under acidic or neutral conditions, protonated aniline (-NH3 + ), and sulfonic acid groups (-SO3 -)(Combined through electrostatic attraction to ensure the uniform oxidative polymerization of aniline at the interface of FeCo2O4 nanoparticles. Uniform coating of polyaniline along the interface of FeCo2O4 nanoparticles can form a continuous conductive network, significantly reducing the interface resistance of FeCo2O4. Moreover, the π-conjugated structure of PANI may undergo electron coupling with metal ions on the surface of FeCo2O4, promoting interfacial charge transfer. At the same time, the uniform PANI coating prevents the direct contact of FeCo2O4 nanoparticles, inhibits aggregation, and maintains a high specific surface area, enhancing the cycling stability of the capacitor. Polyaniline uniformly distributed on the surface of porous FeCo2O4 nanoparticles provides pseudocapacitance through rapid and reversible surface redox reactions. Meanwhile, in cooperation with FeCo2O4, it contributes high specific capacitance through the redox reactions of Co 2 + / Co 3+ and Fe 2+ / Fe 3+ , thus effectively enhancing the specific capacitance. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 FIG. is the infrared spectrum of the FeCo2O4 nanoparticles containing sulfonic groups prepared in Example 1; Figure 2 FIG. is the XRD pattern of the FeCo2O4 / PANI composite material prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION
[0020] To further explain the technical solution of the present invention, the present invention will be elaborated in detail through specific examples below.
[0021] Example 1 This example discloses a preparation method of an FeCo2O4 / PANI composite material, including the following steps: S1. Prepare FeCo2O4 nanoparticles containing sulfonic groups using the sol-gel method; The preparation method of the FeCo2O4 nanoparticles containing sulfonic groups includes the following steps: S11. Dissolve Fe(NO3)3·9H2O, Co(NO3)2·6H2O, and citric acid as a chelating agent in deionized water according to the stoichiometric ratio of Fe and Co; In the preparation of the FeCo2O4 nanoparticles containing sulfonic groups, the amount of substance of the target FeCo2O4 is n1, the amount of substance of citric acid is n2, and the amount of substance of sodium dodecylbenzenesulfonate is n3. Among them, n1 satisfies the following relationships with n2 and n3 respectively: n1:n2 is 1:1.5; n1:n3 is 1:0.5.
[0022] Adjust the pH of the mixed system in step S11 to 3.0 using ammonia water.
[0023] S12. Slowly add sodium dodecylbenzenesulfonate dispersed in water and ethanol dropwise to the mixed system obtained in S11 under stirring conditions; S13. Continuously stir in a 60 °C water bath for 6 hours to form a uniform sol; S14. Let it stand at 80 °C for 12 hours to form a wet gel, and dry it in vacuo at 120 °C for 12 hours to obtain a dry gel; S15. Calcinate at low temperature to obtain FeCo2O4 nanoparticles with sulfonic groups.
[0024] The process conditions for low-temperature calcination in S15 are as follows: 360 °C, for 2 hours under a nitrogen atmosphere.
[0025] S2. Ultrasonically disperse the FeCo2O4 nanoparticles with sulfonic groups in 1 mol / L HCl; The volume ratio of the FeCo2O4 nanoparticles with sulfonic groups to HCl based on the mass of FeCo2O4 is 1 g: 100 ml; S3. Add aniline to the dispersion system obtained in S2; aniline forms a pre-assembly with the sulfonic groups of the FeCo2O4 nanoparticles through electrostatic adsorption and hydrogen bonding; The dosage of aniline and the FeCo2O4 nanoparticles with sulfonic groups is calculated based on aniline and FeCo2O4, and the molar ratio of aniline to FeCo2O4 is 1:8.
[0026] S4. Slowly add ammonium persulfate dropwise to the dispersion system obtained in S3 at a certain rate, controlling the polymerization of aniline pre-assembled on the surface of the FeCo2O4 nanoparticles into polyaniline, and at the same time, the sulfonic groups on the surface of the FeCo2O4 nanoparticles act as doping agents and polymerization sites; The molar ratio of ammonium persulfate to aniline is 1:4; The process conditions for polymerization in step S4 are as follows: Control the temperature at 2 °C; The polymerization time is 6 h; The stirring condition is 150 rpm.
[0027] S5. Wash the solid particles obtained in S4 alternately with 1 mol / L HCl and ethanol, and dry at low temperature to obtain the FeCo2O4 / PANI composite material.
[0028] The infrared spectrum of the FeCo2O4 nanoparticles with sulfonic groups prepared in Example 1 and the XRD of the FeCo2O4 / PANI composite material are respectively as Figure 1 and Figure 2 shown. It can be seen from Figure 1 that at 603 cm -1and 470 cm -1 The positions correspond to the stretching of metal bonds in the octahedral system and the stretching vibration of Fe-O in the tetrahedral system of spinel-structured FeCo2O4, respectively; 1055 cm -1 The position corresponds to the symmetric stretching peak of the S-O bond, and 1186 cm -1 The position corresponds to the infrared absorption peak of S=O; 1608 cm -1 and 3400 cm -1 The position corresponds to the infrared absorption peak of the hydroxyl group. Further combined with Figure 2 , the diffraction peaks of the sulfonic acid group-containing FeCo2O4 prepared in this example can correspond to the standard pattern JCPDS:71-0816 of spinel-type FeCo2O4. A characteristic diffraction peak of polyaniline appears at the position where 2θ is 25.4°. Combined with Figure 1 and Figure 2 It can be seen that the sulfonic acid group-containing FeCo2O4 / PANI composite material is prepared in this example.
[0029] Example 2 The main differences between this example and Example 1 are shown in Table 1.
[0030] Example 3 The main differences between this example and Example 1 are shown in Table 1.
[0031] Example 4 The main differences between this example and Example 1 are shown in Table 1.
[0032] Example 5 The main differences between this example and Example 1 are shown in Table 1.
[0033] Comparative Example This comparative example discloses a preparation method of a FeCo2O4 / PANI composite material, including the following steps: S1. Prepare FeCo2O4 nanoparticles by the sol-gel method; The preparation method of FeCo2O4 nanoparticles includes the following steps: S11. Dissolve Fe(NO3)3·9H2O, Co(NO3)2·6H2O and citric acid as a chelating agent in deionized water according to the stoichiometric ratio of Fe and Co; In the preparation of FeCo2O4 nanoparticles, the amount of substance of the target FeCo2O4 is n1, and the amount of substance of citric acid is n2, where n1 and n2 satisfy the following relationship: n1:n2 is 1:1.5; Adjust the pH of the mixed system in step S11 to 3.0 using ammonia water.
[0034] S12. Continuously stir in a 60 °C water bath for 6 hours to form a homogeneous sol; S13. Let it stand at 80 °C for 12 hours to form a wet gel, and dry it in vacuo at 120 °C for 12 hours to obtain a dry gel; S14. Calcinate at low temperature to obtain FeCo2O4 nanoparticles.
[0035] The process adjustment of the low-temperature calcination in S14 is as follows: 360 °C, 2 hours under a nitrogen atmosphere.
[0036] S2. Ultrasonically disperse FeCo2O4 in 1 mol / L HCl; The mass ratio of FeCo2O4 to the volume of HCl is 1 g: 100 ml; S3. Add aniline to the dispersion system obtained in S2; the molar ratio of aniline to FeCo2O4 is 1:8.
[0037] S4. Slowly drop ammonium persulfate into the dispersion system obtained in S3 at a certain rate, and aniline polymerizes into polyaniline; The molar ratio of ammonium persulfate to aniline is 1:4; The process conditions for the polymerization in step S4 are as follows: Control the temperature at 2 °C; The polymerization time is 6 h; The stirring condition is 150 rpm.
[0038] S5. Wash the solid particles obtained in S4 alternately with 1 mol / L HCl and ethanol, and dry at low temperature to obtain FeCo2O4 / PANI composite materials.
[0039] Table 1 Process parameters for preparing FeCo2O4 / PANI composite materials in Examples 1 to 5
[0040] Respectively, according to BET by the nitrogen adsorption and desorption method, calculate the specific surface areas of the FeCo2O4 nanoparticles and FeCo2O4 / PANI composite materials prepared in Examples 1 to 5 and the comparative examples. The specific test data are shown in Table 2.
[0041] Table 2 Specific surface areas of FeCo2O4 and FeCo2O4 / PANI obtained in Examples 1 to 5 and the comparative examples (m 2 / g)
[0042] The FeCo2O4 / PANI composite materials prepared in Examples 1 to 5 and the comparative example were applied to supercapacitors. Using the FeCo2O4 / PANI composite material as the cathode and activated carbon as the anode, an FeCo2O4 / PANI composite material / / AC hybrid supercapacitor was assembled.
[0043] Fabricating the FeCo2O4 / PANI composite material into a cathode includes the following steps: A1. Mix FeCo2O4 / PANI, a conductive agent, and PVDF in a ratio of 0.8:0.1:0.1, add N-methylpyrrolidone (NMP), and grind into a uniform slurry. Coat the slurry evenly on nickel foam; dry in vacuum at 80 °C for 12 hours; A2. Compact with a tablet press at a pressure of 8 MPa to obtain a cathode sheet.
[0044] The supercapacitor prepared in this example uses 1.0 M H2SO4 as the electrolyte.
[0045] For the fabricated supercapacitor, constant current charge-discharge tests and electrochemical impedance spectroscopy (EIS) tests were carried out. The voltage window for the constant current charge-discharge test was set from 0 V to 1.7 V. The specific capacitance at a current density of 1 A / g, the rate retention at a current density of 10 A / g, and the cycle stability at a current density of 1 A / g were tested respectively; for the electrochemical impedance spectroscopy (EIS) test, the frequency range was 0.01~10 kHz. The intersection of the EIS curve with the real axis in the high-frequency region is the charge transfer resistance (Rct) at the electrode / electrolyte interface of the device, and the sharp peak nearly parallel to the imaginary axis in the low-frequency region is the Warburg resistance. The specific test data are shown in Table 3.
[0046] Table 3 Electrical performance indicators of the supercapacitors made from the composite materials in Examples 1 to 5 and the comparative example
[0047] Combining Tables 1 to 3, it can be seen that compared with the uncontrollable composite of polyaniline and FeCo2O4 nanoparticles in the comparative example, in Examples 1 to 5, sodium dodecylbenzenesulfonate was used as a template agent to fabricate FeCo2O4 nanoparticles with a porous structure, and then the residual sulfonic acid groups after calcination were used to control the pre-assembly of aniline on the FeCo2O4 nanoparticles. Under acidic or neutral conditions, protonated aniline (-NH3 + ), and sulfonic acid group (-SO3 -)(Combined by electrostatic attraction to ensure the uniform oxidative polymerization of aniline at the interface of FeCo2O4 nanoparticles. Polyaniline uniformly coats along the interface of FeCo2O4 nanoparticles to form a continuous conductive network, significantly reducing the interface resistance of FeCo2O4. Moreover, the π-conjugated structure of PANI may undergo electron coupling with metal ions on the surface of FeCo2O4, promoting interfacial charge transfer. At the same time, the uniform PANI coating prevents the direct contact of FeCo2O4 nanoparticles, inhibits aggregation, and maintains a high specific surface area, improving the cycling stability of the capacitor. The polyaniline uniformly distributed on the surface of porous FeCo2O4 nanoparticles provides pseudocapacitance through rapid and reversible surface redox reactions. Meanwhile, in cooperation with FeCo2O4, it contributes to a high specific capacitance through the redox reactions of Co 2+ / Co 3+ and Fe 2+ / Fe 3+ and effectively improves the specific capacitance. Further comparing Examples 1 to 4 with Example 5, when a relatively thick polyaniline is anchored on the surface of porous FeCo2O4 nanoparticles through sulfonic acid groups, the specific capacitance of the composite material will decrease. At the same time, the polyaniline surrounds FeCo2O4, stabilizing the structure of the composite material and improving the conductivity. Therefore, the cycling and rate performance of the obtained supercapacitor show better performance compared to Examples 1 to 4.
Claims
1. A preparation method of FeCo2O4 / PANI composite material, characterized in that: It includes the following steps: S1. Prepare sulfonic acid group-containing FeCo2O4 nanoparticles by sol-gel method; S2. Ultrasonically disperse the sulfonic acid group-containing FeCo2O4 nanoparticles in HCl; S3. Add aniline to the dispersion system obtained in S2; aniline and the sulfonic acid group of FeCo2O4 nanoparticles are pre-assembled by electrostatic adsorption and hydrogen bonding; S4. Slowly drop ammonium persulfate into the dispersion system obtained in S3 at a controlled rate to control the polymerization of aniline pre-assembled on the surface of FeCo2O4 nanoparticles into polyaniline; S5. Wash the solid particles obtained in S4 alternately with HCl and ethanol, and dry at low temperature to obtain FeCo2O4 / PANI composite material.
2. The preparation method according to claim 1, characterized in that: The preparation method of the sulfonic acid group-containing FeCo2O4 nanoparticles includes the following steps: S11. Dissolve Fe(NO3)3·9H2O and Co(NO3)2·6H2O and citric acid as a chelating agent in deionized water according to the stoichiometric ratio of Fe and Co; S12. Slowly drop sodium dodecylbenzenesulfonate dispersed in water and ethanol into the mixed system obtained in S11 under stirring conditions; S13. Continuously stir in a 60°C water bath for 4 to 6 hours to form a uniform sol; S14. Stand at 80°C to form a wet gel, and vacuum dry to obtain a dry gel; S15. Calcinate at low temperature to obtain sulfonic acid group-containing FeCo2O4 nanoparticles.
3. The preparation method according to claim 2, characterized in that: In the preparation of the sulfonic acid group-containing FeCo2O4 nanoparticles, the amount of substance of the target FeCo2O4 is n1, the amount of substance of citric acid is n2, and the amount of substance of sodium dodecylbenzenesulfonate is n3, where n1 satisfies the following relationships with n2 and n3 respectively: n1:n2 is 1:(1.5 to 2); n1:n3 is 1:(0.5 to 1).
4. The preparation method according to claim 2, characterized in that: Use ammonia water to adjust the pH of the mixed system in step S11 to 3 to 4.
5. The preparation method according to claim 2, characterized in that: The process conditions of low-temperature calcination in S15 are: 360°C to 380°C, 2 to 3 hours in a nitrogen atmosphere.
6. The preparation method according to claim 1, characterized in that: The molar ratio of aniline to the sulfonic acid group-containing FeCo2O4 nanoparticles is 1:(8 to 10).
7. The preparation method according to claim 1, characterized in that: The process conditions of polymerization in step S4 are as follows: Control the temperature to be 0°C to 5°C; The polymerization time is 6h to 8h; The stirring condition is 150rpm to 200rpm.
8. Apply the FeCo2O4 / PANI composite material prepared by the preparation method according to any one of claims 1 to 7 to a supercapacitor, characterized in that: Using the FeCo2O4 / PANI composite material as the cathode and activated carbon as the anode, an FeCo2O4 / PANI composite material / / AC hybrid supercapacitor is assembled.
9. The application according to claim 8, wherein: Manufacturing the FeCo2O4 / PANI composite material into a cathode comprises the following steps: A1. Mix FeCo2O4 / PANI, a conductive agent, and PVDF in a ratio of 0.8:0.1:0.1, add N-methylpyrrolidone (NMP), grind into a uniform slurry, and evenly coat the slurry on nickel foam; dry in vacuum at 80 °C for 12 hours; A2. Compress with a tablet press at a pressure of 5 to 10 MPa to obtain a cathode sheet.
10. The application according to claim 8, characterized in that: The supercapacitor uses 0.5 to 1.0 M H2SO4 as the electrolyte.