Preparation method and application of cross-linked polymer material for aqueous ammonium ion battery

Abstract

The invention belongs to the technical field of energy storage materials, and particularly relates to a preparation method and application of a cross-linked high polymer material for an aqueous ammonium ion battery. In the invention, the cross-linked PANI is synthesized by using an in-situ chemical oxidative polymerization technology, and the cross-linked PANI is considered to be an excellent electrode active material for an energy storage system due to high conductivity, large theoretical specific capacity and rapid reaction kinetics and eco-friendly properties in an oxidation-reduction mechanism based on coordination. Compared with the conventional polyaniline, the introduction of the cross-linking agent improves the stability of the cross-linked PANI and is beneficial to the improvement of the electrochemical performance of the battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage materials, and particularly relates to a preparation method and application of a cross-linked polymer material for aqueous ammonium ion batteries. Background Art

[0002] In recent years, with the exhaustion of fossil energy and the aggravation of environmental pollution, the research and development of new energy storage materials have received increasing attention. Existing lithium-ion batteries have disadvantages such as a shortage of lithium metal and the toxicity, inflammability, and explosiveness of organic electrolytes. Aqueous ammonium ion batteries use aqueous solutions as electrolytes, which have the advantages of environmental friendliness, safety, and low cost, and have good development prospects. However, at the same time, the limited electrochemical performance of the energy storage materials for aqueous ammonium ion batteries restricts their commercial development and has become one of the current hot research topics. As the center of the battery redox reaction, the electrode material is a medium that is responsible for both ion and electron transfer and separation, and largely determines the performance of the entire battery. Therefore, the exploration of electrode materials for aqueous ammonium ion batteries is crucial. Conductive polymers, such as polyaniline (PANI), have been considered excellent electrode active materials for energy storage systems due to their high conductivity, large theoretical specific capacity, fast reaction kinetics in the coordination-based redox mechanism, and eco-friendly properties. Summary of the Invention

[0003] The present invention synthesizes cross-linked PANI using in-situ chemical oxidative polymerization technology. Compared with conventional polyaniline, the introduction of a cross-linking agent improves the stability of cross-linked PANI and is beneficial to the improvement of the battery's electrochemical performance.

[0004] To achieve the above object, the present invention provides a preparation method and application of a cross-linked polymer material for aqueous ammonium ion batteries.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A preparation method of a cross-linked polymer material, comprising the following steps: adding a diphenylamine solution to a mixed solution of aniline, melamine, and hydrochloric acid solution, and then adding an ammonium persulfate solution, and slowly stirring and reacting at 0 - 4 °C for ≥ 24 hours until a green color in the state of conductive emeraldine imine appears to synthesize cross-linked PANI.

[0007] Further, in the above preparation method, the amount of aniline used is 294 μL.

[0008] Further, in the above preparation method, the amount of melamine used is 9 mg.

[0009] Further, in the above preparation method, the hydrochloric acid solution is: 100 mL of 1 M HCl solution.

[0010] 5. The preparation method according to claim 1, characterized in that the diphenylamine solution is: 21.8 mg of diphenylamine is dissolved in 5 mL of anhydrous ethanol.

[0011] Furthermore, in the above preparation method, the ammonium persulfate solution is: 0.75 g of ammonium persulfate is dissolved in 5 mL of 1 M HCl.

[0012] Application of the cross-linked PANI prepared by any of the preparation methods described above as an electrode material for aqueous ammonium ion batteries.

[0013] Further, the above application method is as follows: cross-linked PANI is mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone, and after sufficient grinding, the mixture is evenly coated on the surface of the functionalized flexible carbon cloth current collector material to obtain a battery electrode.

[0014] Furthermore, in the above application, the mass ratio of cross-linked PANI: polyvinylidene fluoride: superconducting carbon black is 7:2:1.

[0015] Furthermore, in the above application, the amount of N-methylpyrrolidone used is just enough to soak the three powders of cross-linked PANI, polyvinylidene fluoride, and superconducting carbon black to form a slurry therewith.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention uses melamine as a cross-linking agent and adopts an in-situ polymerization method to synthesize cross-linked PANI.

[0018] 2. Compared with conventional polyaniline, the introduction of the crosslinking agent in the present invention improves the stability of the crosslinked PANI, which is beneficial to the improvement of the electrochemical performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a scanning electron microscope image of the PANI and the cross-linked PANI synthesized in Example 1, wherein a is PANI and b is cross-linked PANI.

[0020] Figure 2 This is a cyclic voltammetry curve of the cross-linked PANI battery electrode prepared in Example 2 at a scan rate of 10 mV / s.

[0021] Figure 3 The PANI battery electrode and the cross-linked PANI battery electrode prepared in Example 3 are -1 Charge and discharge curves at current density.

[0022] Figure 4 The PANI battery electrode and the cross-linked PANI battery electrode prepared in Example 4 were -1 Charge and discharge curves at current density.

[0023] Figure 5 is the cyclic voltammetry curve of the cross-linked PANI battery electrode prepared in Example 5 during 1000 charge-discharge cycles at a current density of 10 A g -1 The current density is

[0024] Figure 6 are the chemical structural formulas of PANI and cross-linked PANI. Detailed implementation manners

[0025] Example 1

[0026] A preparation method of a cross-linked polymer material for an aqueous ammonium ion battery, comprising the following steps:

[0027] 1) Synthesize cross-linked PANI by chemical oxidative polymerization: First, dissolve 294 μL of aniline and 9 mg of melamine in 100 mL of 1.0 M HCl solution; dissolve 21.8 mg of diphenylamine in 5 mL of absolute ethanol; add the diphenylamine solution to the hydrochloric acid solution containing aniline and melamine. Finally, gradually add 5 mL of 1 M HCl solution (used as an oxidant) containing 0.75 g of ammonium persulfate dropwise to the above solution, and stir the mixed solution at 0 °C for 24 h until a green color in the form of emeraldine imine appears, thus synthesizing cross-linked PANI.

[0028] 2) Synthesize PANI by chemical oxidative polymerization: First, dissolve 294 μL of aniline in 100 mL of 1.0 M HCl solution. Then gradually add 5 mL of 1 M HCl solution (used as an oxidant) containing 0.75 g of ammonium persulfate dropwise to the above solution, and stir the mixed solution at 0 °C for 24 h.

[0029] Figure 1 are the scanning electron microscope images of the PANI and cross-linked PANI synthesized in Example 1, where Figure 1 a is PANI, Figure 1 b is cross-linked PANI. It can be seen from the scanning electron microscope images that compared with PANI, the morphology of cross-linked PANI has changed greatly, proving successful synthesis.

[0030] Example 2

[0031] A preparation method of a cross-linked polymer material for an aqueous ammonium ion battery, comprising the following steps:

[0032] 1) Cross-linked PANI was synthesized by chemical oxidative polymerization: First, 294 μL of aniline and 9 mg of melamine were dissolved in 100 mL of 1.0 M HCl solution; 21.8 mg of diphenylamine was dissolved in 5 mL of absolute ethanol; the diphenylamine solution was added to the hydrochloric acid solution containing aniline and melamine. Finally, 5 mL of 1 M HCl solution containing 0.75 g of ammonium persulfate (used as an oxidant) was added dropwise to the above solution, and the mixed solution was stirred at 0 °C for 24 h until a green color in the emerald imine state appeared, and cross-linked PANI was synthesized.

[0033] 2) Cross-linked PANI, polyvinylidene fluoride, superconducting carbon black, and N-methylpyrrolidone were mixed to form a slurry. The amount of N-methylpyrrolidone was just enough to infiltrate the three material powders. After thorough grinding, it was evenly coated on the surface of a flexible carbon cloth current collector material to obtain a cross-linked PANI battery electrode; by mass ratio, cross-linked PANI: polyvinylidene fluoride: superconducting carbon black = 7:2:1. After drying and weighing, the mass of the cross-linked PANI active material was 1.81 mg.

[0034] Figure 2 It is the cyclic voltammogram of the cross-linked PANI battery electrode prepared in Example [2] at a scan rate of 10 mV s -1 The voltage range of cross-linked PANI can be determined to be -0.5 to 0.9 V. Figure 2 from this.

[0035] Example 3

[0036] A preparation method of a cross-linked polymer material for an aqueous ammonium ion battery includes the following steps:

[0037] 1) Cross-linked PANI was synthesized by chemical oxidative polymerization: First, 294 μL of aniline and9 mg of melamine were dissolved in 100 mL of 1.0 M HCl solution; 21.8 mg of diphenylamine was dissolved in 5 mL of absolute ethanol; the diphenylamine solution was added to the hydrochloric acid solution containing aniline and melamine. Finally, 5 mL of 1 M HCl solution containing 0.75 g of ammonium persulfate (used as an oxidant) was added dropwise to the above solution, and the mixed solution was stirred at 0 °C for 24 h until a green color in the emerald imine state appeared, and cross-linked PANI was synthesized.

[0038] 2) PANI was synthesized by chemical oxidative polymerization: First, 294 μL of aniline was dissolved in 100 mL of 1.0 M HCl solution. Then, 5 mL of 1 M HCl solution containing 0.75 g of ammonium persulfate (used as an oxidant) was added dropwise to the above solution, and the mixed solution was stirred at 0 °C for 24 h.

[0039] 3) PANI / cross-linked PANI was mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone to form a slurry. The amount of N-methylpyrrolidone was just enough to soak the three material powders. After sufficient grinding, it was evenly coated on the surface of the flexible carbon cloth current collector material to obtain PANI battery electrode / cross-linked PANI battery electrode; according to the mass ratio, PANI / cross-linked PANI: polyvinylidene fluoride: superconducting carbon black = 7:2:1. After drying, the mass of PANI active material was 1.80 mg, and the mass of cross-linked PANI active material was 1.81 mg.

[0040] Figure 3 The battery electrode prepared in Example 3 is 1A g -1 The charge and discharge curves under current density. It can be seen from the charge and discharge curves that PANI -1 The capacity at the current density is 116.20 mAh g -1 , and the capacity of cross-linked PANI can reach 142.87 mAh-1g -1 .

[0041] Example 4

[0042] A method for preparing a cross-linked polymer material for an aqueous ammonium ion battery comprises the following steps:

[0043] 1) Synthesize cross-linked PANI by chemical oxidative polymerization: First, dissolve 294 μL aniline and 9 mg melamine in 100 mL 1.0 M HCl solution; dissolve 21.8 mg diphenylamine in 5 mL anhydrous ethanol; add the diphenylamine solution to the hydrochloric acid solution containing aniline and melamine. Finally, add 5 mL 1 M HCl solution containing 0.75 g ammonium persulfate (used as an oxidant) dropwise to the above solution, and stir the mixed solution at 0 ° C for 24 h until the green color of emeraldine appears, thereby synthesizing cross-linked PANI.

[0044] 2) Synthesis of PANI by chemical oxidative polymerization: First, 294 μL of aniline was dissolved in 100 mL of 1.0 M HCl solution. Then, 5 mL of 1 M HCl solution containing 0.75 g of ammonium persulfate (used as an oxidant) was added dropwise to the above solution, and the mixed solution was stirred at 0°C for 24 h.

[0045] 3) PANI / cross-linked PANI was mixed with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone to form a slurry. The amount of N-methylpyrrolidone was just enough to soak the three material powders. After sufficient grinding, it was evenly coated on the surface of the flexible carbon cloth current collector material to obtain PANI battery electrode / cross-linked PANI battery electrode; according to the mass ratio, PANI / cross-linked PANI: polyvinylidene fluoride: superconducting carbon black = 7:2:1. After drying, the mass of PANI active material was 1.78 mg, and the mass of cross-linked PANI active material was 1.82 mg.

[0046] Figure 4 The battery electrode prepared in Example 4 is 10Ag -1 The charge and discharge curves under current density. It can be seen from the charge and discharge curves that PANI -1 The capacity at the current density is 57.71 mAh g -1 , and the capacity of cross-linked PANI can reach 69.99 mAh-1g -1 .

[0047] Example 5

[0048] A method for preparing a cross-linked polymer material for an aqueous ammonium ion battery comprises the following steps:

[0049] 1) Synthesize cross-linked PANI by chemical oxidative polymerization: First, dissolve 294 μL aniline and 9 mg melamine in 100 mL 1.0 M HCl solution; dissolve 21.8 mg diphenylamine in 5 mL anhydrous ethanol; add the diphenylamine solution to the hydrochloric acid solution containing aniline and melamine. Finally, add 5 mL 1 M HCl solution containing 0.75 g ammonium persulfate (used as an oxidant) dropwise to the above solution, and stir the mixed solution at 0 ° C for 24 h until the green color of emeraldine appears, thereby synthesizing cross-linked PANI.

[0050] 2) Mix cross-linked PANI, polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone to form a slurry. The amount of N-methylpyrrolidone used is just enough to soak the powders of the three materials. After sufficient grinding, evenly apply it to the surface of the flexible carbon cloth current collector material to obtain a cross-linked PANI battery electrode; according to the mass ratio, cross-linked PANI: polyvinylidene fluoride: superconducting carbon black = 7:2:1. After drying and weighing, the mass of the cross-linked PANI active material is 1.85 mg.

[0051] Figure 5 For cross-linking PANI at 10Ag -1 Cyclic stability diagram of 1000 charge and discharge cycles at the current density. Figure 5 It can be seen that the capacity retention rate of the cross-linked PANI is 33.68%.

Claims

1. A method for preparing a crosslinked polymer material, characterized in that It includes the following steps: adding diphenylamine solution to the mixed solution of aniline, melamine and hydrochloric acid solution, then adding ammonium persulfate solution, and slowly stirring and reacting at 0-4 °C for ≥24 hours until a green color in the state of conductive emeraldine imine appears to synthesize cross-linked PANI.

2. The preparation method according to claim 1, characterized in that, The dosage of aniline is 294 μL.

3. The preparation method according to claim 1, characterized in that, The dosage of melamine is 9 mg.

4. The preparation method according to claim 1, characterized in that, The hydrochloric acid solution is: 100 mL of 1M HCl solution.

5. The preparation method according to claim 1, characterized in that, The diphenylamine solution is: 21.8 mg of diphenylamine dissolved in 5 mL of absolute ethanol.

6. The preparation method according to claim 1, wherein The ammonium persulfate solution is: 0.75 g of ammonium persulfate dissolved in 5 mL of 1M HCl.

7. Application of the cross-linked PANI prepared by the preparation method according to any one of claims 1-6 as an electrode material for an aqueous ammonium ion battery.

8. The application according to claim 7, wherein The method is as follows: mixing cross-linked PANI with polyvinylidene fluoride, superconducting carbon black and N-methylpyrrolidone, fully grinding and then evenly coating it on the surface of a functionalized flexible carbon cloth current collector material to obtain a battery electrode.

9. The application according to claim 8, wherein By mass ratio, cross-linked PANI: polyvinylidene fluoride: superconducting carbon black = 7:2:

1.

10. The application according to claim 8, characterized in that, The dosage of N-methylpyrrolidone is just enough to infiltrate the three powders of cross-linked PANI, polyvinylidene fluoride and superconducting carbon black to form a slurry with them.

Images