Preparation method and application of organic-inorganic hybrid MoO3atPpy composite material with electrochemical performance

Abstract

The invention belongs to the technical field of novel electrode materials, and particularly relates to a preparation method and application of an organic-inorganic hybrid MoO3atPpy composite material with electrochemical performance. The preparation method comprises the following steps: dispersing a proper amount of commercial MoO3 in deionized water, violently stirring for 0.5-1 hour, adding a proper amount of pyrrole monomer, slowly adding a precooled ammonium persulfate aqueous solution into the suspension while violently stirring, reacting for 6 hours at the temperature of 0 DEG C, centrifugally collecting dark precipitate, washing with ethanol and deionized water, and finally drying to obtain the MoO3 / pyrrole composite material. And drying the obtained precipitate at 60 DEG C overnight. The organic-inorganic composite electrode material obtained by a two-step method shows excellent electrochemical performance when being applied to the mixed zinc-aluminum ion battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of novel electrode materials and can be applied to the field of aqueous ion batteries. Specifically, it relates to a preparation method and application of an organic-inorganic hybrid MoO3@Ppy composite material with electrochemical performance. Background Art

[0002] With the increasing severity of the energy crisis and environmental deterioration, it is urgent to develop and utilize clean, low-cost, and renewable energy sources. New energy resources such as wind energy, solar energy, tidal energy, and geothermal energy show a serious imbalance between supply and demand in terms of time and space. Therefore, advocating the development of efficient conversion and storage technologies for various new and clean energy sources has become a hot topic in current international research. Aqueous batteries have gradually come into people's view due to their low cost, non-toxic, and pollution-free unique advantages.

[0003] Taking aqueous zinc-ion batteries as an example, their low cost, high safety, low potential, and relatively high energy density are considered to be the most promising energy storage batteries. However, the electrode material has a great impact on the energy storage effect of aqueous batteries. MoO3 is an excellent choice for the positive electrode material due to its rich reserves and adjustable valence states. However, under weakly acidic conditions, molybdenum trioxide has problems such as irreversible phase transformation and unremarkable capacity. Polymerizing pyrrole monomers with MoO3, and then making H + slowly enter the interior of MoO3 to ensure its structural stability. Summary of the Invention

[0004] The present invention provides a preparation method and application of an organic-inorganic hybrid MoO3@Ppy composite material with electrochemical performance. The MoO3@Ppy composite material is obtained through a two-step method, and the MoO3@Ppy composite material exhibits excellent electrochemical performance when applied to aqueous zinc-aluminum ion batteries.

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

[0006] A preparation method of a MoO3@Ppy composite material, comprising the following steps:

[0007] 1) First disperse MoO3 in deionized water, stir vigorously, and then add pyrrole monomers to obtain a suspension;

[0008] 2) Slowly add a pre-cooled aqueous ammonium persulfate solution to the above suspension under vigorous stirring, stir and react in a low-temperature water bath, centrifuge to collect the dark precipitate, and wash it with ethanol and deionized water;

[0009] 3) Dry the obtained precipitate to obtain the MoO3@Ppy composite material.

[0010] Further, in the above preparation method, in step 1), the vigorous stirring time is 0.5 - 1 h.

[0011] Further, in the above preparation method, in step 1), the dosage of MoO3 is 100 mg, and the dosage of pyrrole monomer is 30 - 100 μL.

[0012] Furthermore, in the above preparation method, the molar ratio of ammonium persulfate to pyrrole monomer is 1:1.

[0013] Further, in the above preparation method, in step 2), the low-temperature water bath stirring reaction is carried out under ice-water bath at 0 °C for 6 h.

[0014] Further, in the above preparation method, in step 3), the drying condition is drying overnight at 60 °C.

[0015] Application of the MoO3@Ppy composite material prepared by the preparation method described in any one of the above as a positive electrode material in an aqueous zinc-aluminum ion battery.

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

[0017] 1. The MoO3@Ppy composite electrode material provided by the present invention utilizes the inorganic-organic synergistic effect to coat a layer of Ppy on the surface of the MoO3 active material, protecting the MoO3 with low conductivity and easy structural collapse under weak acidic conditions like a shell layer, ensuring high conductivity of the composite material.

[0018] 2. The rich valence states and large natural reserves of MoO3 provide great prospects for the application of the MoO3@Ppy composite material.

[0019] 3. The surface of Ppy has rich functional groups, guaranteeing the conductivity of the composite material. Description of the Drawings

[0020] Figure 1 are scanning electron microscope pictures of the MoO3@Ppy composite material prepared in Example 1 at different magnifications.

[0021] Figure 2 are scanning electron microscope pictures of the MoO3 electrode material at different magnifications.

[0022] Figure 3 are scanning electron microscope pictures of the ppy electrode material prepared in Comparative Example 1 at different magnifications.

[0023] Figure 4 are XRD spectra of the MoO3@Ppy composite material prepared in Example 1, the Ppy prepared in Comparative Example 1, and MoO3.

[0024] Figure 5It is the charge-discharge curve graph of the MoO3@Ppy composite material prepared in Example 1. Detailed implementation mode

[0025] Example 1

[0026] Disperse 100 mg of commercial MoO3 in 30 mL of deionized water first, stir vigorously for 30 min, then add 60 μL of pyrrole monomer to obtain a suspension. Then, slowly add the precooled aqueous ammonium persulfate (APS) solution (the molar ratio of APS to pyrrole monomer is 1:1) to the above suspension under vigorous stirring. After reacting at 0 °C for 6 h, centrifuge to collect the dark precipitate, and wash it with ethanol and deionized water. Finally, dry the obtained precipitate at 60 °C overnight to obtain the MoO3@Ppy composite material.

[0027] Figure 1 It is the scanning electron microscope pictures of the MoO3@Ppy composite material prepared in Example 1 at different magnifications. It can be seen that there is a layer of film, namely the Ppy film, on the periphery of the rod-shaped material. This result can be further proved by the XRD comparison graph of the MoO3@Ppy composite material, Ppy and MoO3 ( Figure 4 )

[0028] Figure 5 It is the electrochemical performance and life graph of the MoO3@Ppy composite material prepared in Example 1 at 5 A g -1 -1, and it can be clearly seen that it still has a good retention rate after 2800 cycles.

[0029] Example 2

[0030] Disperse 100 mg of commercial MoO3 in 30 mL of deionized water first, stir vigorously for 30 min, then add 30 μL of pyrrole monomer to obtain a suspension. Then, slowly add the precooled aqueous ammonium persulfate (APS) solution (the molar ratio of APS to pyrrole monomer is 1:1) to the above suspension under vigorous stirring. After reacting at 0 °C for 6 h, centrifuge to collect the dark precipitate, and wash it with ethanol and deionized water. Finally, dry the obtained precipitate at 60 °C overnight to obtain the MoO3@Ppy composite material.

[0031] Example 3

[0032] First, disperse 100 mg of commercial MoO3 in 30 mL of deionized water and stir vigorously for 30 min. Then, add 100 μL of pyrrole monomer to obtain a suspension. Next, slowly add the pre-cooled aqueous ammonium persulfate (APS) solution (the molar ratio of APS to pyrrole monomer is 1:1) to the above suspension under vigorous stirring. After reacting at 0 °C for 6 h, centrifuge to collect the dark precipitate, and wash it with ethanol and deionized water. Finally, dry the obtained precipitate at 60 °C overnight to obtain the MoO3@Ppy composite material.

[0033] Comparative Example 1

[0034] Preparation of polypyrrole (Ppy): Slowly add the pre-cooled aqueous ammonium persulfate (APS) solution (the molar ratio of APS to pyrrole monomer is 1:1) to 60 μL of pyrrole monomer under vigorous stirring. After reacting at 0 °C for 6 h, centrifuge to collect the dark precipitate, and wash it with ethanol and deionized water. Finally, dry the obtained precipitate at 60 °C overnight.

[0035] Figure 3 It is the scanning electron microscope images of Ppy prepared in Comparative Example 1 at different magnification ratios. It has a larger specific surface area, which is more conducive to attaching to the material surface.

[0036] Figure 4 It is the XRD schematic diagrams of three materials: MoO3, MoO3 + 60 μL Ppy, and 60 μL Ppy, which can prove the synthesis of the MoO3@Ppy composite material.

[0037] Example 4

[0038] To further test the electrochemical performance, we assembled a hybrid zinc-aluminum ion battery:

[0039] Its overall structure includes: a positive electrode, an electrolyte, and a negative electrode. The main material of the positive electrode is the MoO3@Ppy composite material. The mass ratio of the MoO3@Ppy composite material, the conductive agent (acetylene black), and the binder (PVDF) is 7:2:1. The coated electrode sheet is dried at 60 °C for 8 h, and the loading of the positive electrode is 1 mg. The negative electrode is zinc metal (zinc foil). The main components of the electrolyte include zinc salt and aluminum salt. To avoid additional influence caused by anions, salt solutions with the same anion are selected. Preferably, the final determined effective concentration of the electrolyte is 1 mol ZnSO4 + 0.5 mol Al2(SO4)3.

Claims

1. A method for preparing a MoO3@Ppy composite material, characterized in that: The steps include: 1) MoO3 is first dispersed in deionized water, stirred vigorously, and then pyrrole monomer is added to obtain a suspension; 2) slowly adding a pre-cooled aqueous solution of ammonium persulfate to the above suspension under vigorous stirring, stirring the reaction in a low-temperature water bath, collecting the dark precipitate by centrifugation, and washing with ethanol and deionized water; 3) Drying the obtained precipitate to obtain a MoO3@Ppy composite material.

2. The preparation method according to claim 1, characterized in that: In step 1), the amount of MoO3 used is 100 mg, and the amount of pyrrole monomer used is 30-100 μL.

3. The preparation method according to claim 1, characterized in that: In step 1), the vigorous stirring time is 0.5-1h.

4. The preparation method according to claim 2, characterized in that: The molar ratio of the ammonium persulfate to the pyrrole monomer is 1:

1.

5. The preparation method according to claim 1, characterized in that: In step 2), the low-temperature water bath stirring reaction is stirred in an ice-water bath at 0°C for 6 hours.

6. The preparation method according to claim 1, characterized in that: In step 3), the drying condition is drying at 60° C. overnight.

7. Use of the MoO3@Ppy composite material prepared by the preparation method described in any one of claims 1 to 6 as a positive electrode material in an aqueous zinc-aluminum ion battery.

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