Co-NiPc-MoS2 / MXene ternary composite material as well as preparation method and application thereof

Abstract

The invention discloses a Co-NiPc-MoS2 / MXene ternary composite material and a preparation method and application thereof.The preparation method comprises the following steps that after MXene powder is dispersed in deionized water, a sulfur source, a reducing agent and a molybdenum source are sequentially added and evenly dispersed, and a mixed solution A is obtained; dissolving metal phthalocyanine in absolute ethyl alcohol to obtain a mixed solution B; dropwise adding the mixed solution B into the mixed solution A to obtain a precursor solution; and carrying out solvothermal reaction on the precursor solution at the temperature of 160 to 200 DEG C, so as to obtain the Co-NiPc-MoS2 / MXene ternary composite material. The problem that conductivity, active sites and structural stability in an existing electrode material are difficult to consider at the same time is effectively solved. When the prepared composite material is used as a supercapacitor electrode, high specific capacitance and excellent rate capability are shown, and the comprehensive electrochemical performance of a supercapacitor is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage materials technology, and in particular to a ternary nanocomposite material for high-performance supercapacitors and its preparation method. Background Technology

[0002] Supercapacitors, as a novel energy storage device situated between traditional capacitors and batteries, have shown broad application prospects in new energy vehicles, smart grids, and portable electronic devices due to their outstanding advantages such as high power density, fast charging and discharging speed, and long cycle life. Electrode materials are the core determinant of supercapacitor performance; ideal electrode materials must possess high conductivity, large specific surface area, abundant electrochemical active sites, and a stable microstructure.

[0003] Two-dimensional materials have attracted widespread attention in the field of electrochemical energy storage due to their unique layered structure and excellent physicochemical properties. Among them, MXene materials possess metallic-grade conductivity and good hydrophilicity, but their layers are prone to stacking during preparation and cycling, leading to a reduction in active area and an extension of ion transport paths, limiting further improvements in specific capacity. Molybdenum disulfide (MoS2) is another typical two-dimensional material; its layered structure provides ideal channels for ion insertion / extraction. However, its intrinsic conductivity is poor, and it is prone to structural collapse during electrochemical cycling. Metal phthalocyanines are a class of macrocyclic conjugated molecules, whose central metal ions can provide highly efficient redox reaction active sites. However, their poor conductivity and tendency to aggregate intermolecularly severely restrict their application in electrode materials.

[0004] Currently, researchers have attempted to construct binary composite materials such as MXene / MoS2 to synergistically improve performance. However, these binary materials still have shortcomings in resolving the contradiction between conductivity, active sites, and structural stability. For example, simple physical mixing makes it difficult to achieve strong coupling between components, resulting in poor interfacial stability; if metal phthalocyanines are directly composited with a conductive substrate, their loading and dispersion uniformity are difficult to control, and they are prone to agglomeration, thus affecting the rapid transport of ions and electrons. These problems ultimately make it difficult for the electrode material to simultaneously meet the requirements of high-performance supercapacitors in terms of specific capacitance, rate performance, and long-cycle stability. Therefore, developing a novel ternary composite material that can achieve complementary advantages among components, structural stability, and abundant active interfaces has become a key problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to propose a method for preparing a Co-NiPc@MoS2 / MXene ternary composite material to solve the problem that it is difficult to synergistically improve conductivity, active sites and structural stability in existing supercapacitor electrode materials, thereby improving the specific capacitance, rate performance and cycle stability of the electrode material.

[0006] A method for preparing a Co-NiPc@MoS2 / MXene ternary composite material includes the following steps: After dispersing MXene powder in deionized water, sulfur source, reducing agent and molybdenum source are added in sequence and dispersed evenly to obtain mixture A; Metal phthalocyanine was dissolved in anhydrous ethanol to obtain mixture B; The mixture B is added dropwise to the mixture A to obtain the precursor solution; The precursor solution was subjected to a solvothermal reaction at 160~200℃ to obtain a Co-NiPc@MoS2 / MXene ternary composite material.

[0007] As a preferred embodiment, the mass ratio of MXene powder, molybdenum source, sulfur source, reducing agent and metal phthalocyanine is 1 : (7.0~8.5) : (90~110) : (9~11) : (0.8~1.2).

[0008] As a preferred embodiment, the MXene powder is Ti3C2T. x powder.

[0009] As a preferred embodiment, the sulfur source is selected from one or more of thiourea, thioacetamide, and L-cysteine; the molybdenum source is one or more of ammonium molybdate tetrahydrate, potassium molybdate, and molybdic acid; and the reducing agent is one or more of glucose, hydrazine hydrate, and ascorbic acid.

[0010] As a preferred embodiment, the metal phthalocyanine is a mixture of cobalt phthalocyanine and nickel phthalocyanine.

[0011] As a preferred embodiment, the mass ratio of cobalt phthalocyanine to nickel phthalocyanine is (0.8~1.2):(0.8~1.2).

[0012] As a preferred embodiment, the temperature of the solvothermal reaction is 180°C.

[0013] A Co-NiPc@MoS2 / MXene ternary composite material obtained by the aforementioned preparation method.

[0014] The application of a Co-NiPc@MoS2 / MXene ternary composite material as an electrode material in supercapacitors, as described above.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention successfully constructed a ternary composite material via a one-step solvothermal method, a process that is simple and efficient. MXene serves as a conductive framework, ensuring high conductivity of the electrode; in-situ grown MoS2 effectively suppresses the stacking of MXene sheets, providing a larger specific surface area and more ion transport channels; uniformly anchored bimetallic phthalocyanine molecules contribute abundant redox active sites, and the three components generate a significant synergistic effect through strong interfacial coupling.

[0016] When the ternary composite material prepared by this invention is used as a supercapacitor electrode, it exhibits electrochemical performance far superior to that of single-component and binary composite materials, specifically high specific capacitance, excellent rate performance (maintaining high capacity even at high current density), and outstanding long-cycle stability.

[0017] The structural design strategy of this material provides a new approach for developing high-performance, long-life MXene-based composite electrode materials, and has broad application prospects in high-power energy storage devices. Attached Figure Description

[0018] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a scanning electron microscope image of the Co-NiPc@MoS2 / MXene material prepared in Example 1 of this invention; Figure 2 This is the XRD pattern of Embodiment 1 in this invention; Figure 3 Comparison of cyclic voltammetry curves of Co-NiPc@MoS2 / MXene prepared in Example 1 and Comparative Examples 1-4 of this invention at the same scan rate; Figure 4 This is a comparison diagram of constant current charging and discharging of Example 1 and Comparative Examples 1-4 under the same current density in this invention; Figure 5 This is an impedance comparison diagram of Embodiment 1 and Comparative Examples 1-4 in this invention; Figure 6 This is a comparison chart of the specific capacitance obtained from the CV curves of Example 1 and Comparative Examples 1 to 4 in this invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0020] Example 1 This embodiment provides a Co-NiPc@MoS2 / MXene ternary composite material and its preparation method, specifically including the following steps: S1. Accurately weigh 10 mg of Ti3C2T x After MXene powder is dissolved in 20 mL of deionized water, it is ultrasonically treated at room temperature for 30 min until a uniform and stable black dispersion is formed for later use. S2. Add 1.0 g thiourea, 100 mg anhydrous glucose and 76.7 mg ammonium molybdate tetrahydrate to the black dispersion obtained in step S1 in sequence, and then stir on a magnetic stirrer for 30 min to mix evenly to obtain mixture A. S3. Accurately weigh 5 mg of cobalt phthalocyanine and 5 mg of nickel phthalocyanine, add them to 10 mL of anhydrous ethanol, sonicate for 15 min to fully dissolve and form a homogeneous mixture B. Under continuous magnetic stirring, slowly add mixture B to mixture A. After mixing is complete, continue stirring for 1 hour to form the final precursor solution. S4. Transfer all the precursor solution to a 50 mL stainless steel high-pressure reactor lined with polytetrafluoroethylene. After sealing, place the reactor in a drying oven and set the temperature of the drying oven to 180℃. After reacting for 24 hours, turn off the heating and allow the reactor to cool naturally to room temperature. Open the reactor and filter the reaction product. Wash the product three times alternately with deionized water and anhydrous ethanol. Finally, place the solid product in a vacuum drying oven at 60℃ and dry for 12 hours. After grinding, black Co-NiPc@MoS2 / MXene ternary composite powder is obtained.

[0021] Comparative Example 1 The only difference between this embodiment and Example 1 is that in step S3, only 10 mg of nickel phthalocyanine is added, and cobalt phthalocyanine is not added. The resulting product is a NiPc@MoS2 / MXene composite material.

[0022] Comparative Example 2 The only difference between this embodiment and Example 1 is that in step S3, only 10 mg of cobalt phthalocyanine is added, and nickel phthalocyanine is not added. The resulting product is a CoPc@MoS2 / MXene composite material.

[0023] Comparative Example 3 The only difference between this comparative example and Example 1 is that the precursor solution does not contain metal phthalocyanine, and the resulting product is a MoS2 / MXene binary composite material.

[0024] Comparative Example 4 This comparative example directly used 10 mg Ti3C2T x MXene powder was used as a control sample.

[0025] Testing and Performance Analysis Using the materials prepared in Examples 1 and Comparative Examples 1-4 as active substances, a slurry was prepared by mixing acetylene black and polyvinylidene fluoride at a mass ratio of 8:1:1. This slurry was coated onto nickel foam, vacuum dried at 60°C for 12 hours, and then pressed into a sheet to obtain the working electrode. A three-electrode system was used, with 1 M KOH solution as the electrolyte, an Hg / HgO electrode as the reference electrode, and a platinum sheet as the counter electrode. The tests were performed using an electrochemical workstation (Shanghai Chenhua, CHI660E).

[0026] from Figure 1 It can be seen that MoS2 grows uniformly on MXene sheets in the form of nanoflowers, forming a good three-dimensional porous structure.

[0027] from Figure 2 The presence of characteristic diffraction peaks for MXene, MoS2, and metal phthalocyanine in the composite material confirms the successful preparation of the ternary composite material.

[0028] Figure 3 The cyclic voltammetry curves show that Example 1 has the largest closed area, indicating that it has the highest specific capacitance. Figure 4 The constant current charge-discharge curves show that Example 1 has the longest discharge time, which is consistent with the CV test results. Figure 5 The electrochemical impedance spectroscopy showed that Example 1 had the smallest charge transfer resistance, indicating that it had faster charge transport kinetics.

[0029] from Figure 6 It can be seen that at 0.5 A·g -1 At the given current density, the specific capacitance of Example 1 reaches 1088.57 F·g. -1 The Co-NiPc@MoS2 / MXene prepared in this invention exhibits a significantly higher specific capacitance than the composite material modified with only a single metal phthalocyanine, demonstrating a synergistic effect between the cobalt / nickel bimetallic centers, which jointly enhance the electrochemical performance of the material, indicating its broad application prospects in supercapacitors.

[0030] The above results show that the Co-NiPc@MoS2 / MXene ternary composite material prepared in this invention has excellent electrochemical performance. Its unique three-dimensional porous structure and the synergistic effect of each component effectively improve the specific capacitance and rate performance of the material.

[0031] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a Co-NiPc@MoS2 / MXene ternary composite material, characterized in that, Includes the following steps: After dispersing MXene powder in deionized water, sulfur source, reducing agent and molybdenum source are added in sequence and dispersed evenly to obtain mixture A; Metal phthalocyanine was dissolved in anhydrous ethanol to obtain mixture B; The mixture B is added dropwise to the mixture A to obtain the precursor solution; The precursor solution was subjected to a solvothermal reaction at 160~200℃ to obtain a Co-NiPc@MoS2 / MXene ternary composite material.

2. The preparation method of the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 1, characterized in that, The mass ratio of MXene powder, molybdenum source, sulfur source, reducing agent and metal phthalocyanine is 1 : (7.0~8.5) : (90~110) : (9~11) : (0.8~1.2).

3. The preparation method of the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 1 or 2, characterized in that, The MXene powder is Ti3C2T. x powder.

4. The preparation method of the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 1 or 2, characterized in that, The sulfur source is selected from one or more of thiourea, thioacetamide, and L-cysteine; the molybdenum source is selected from one or more of ammonium molybdate tetrahydrate, potassium molybdate, and molybdic acid; and the reducing agent is selected from one or more of glucose, hydrazine hydrate, and ascorbic acid.

5. The method for preparing the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 1 or 2, characterized in that, The metal phthalocyanine is a mixture of cobalt phthalocyanine and nickel phthalocyanine.

6. The preparation method of the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 5, characterized in that, The mass ratio of cobalt phthalocyanine to nickel phthalocyanine is (0.8~1.2):(0.8~1.2).

7. The preparation method of the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 1, characterized in that, The temperature of the solvothermal reaction is 180°C.

8. A Co-NiPc@MoS2 / MXene ternary composite material obtained by the preparation method according to any one of claims 1 to 7.

9. The use of the Co-NiPc@MoS2 / MXene ternary composite material as described in claim 8 as an electrode material in a supercapacitor.

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