CN113436910A

CN113436910A - Preparation method of high-conductivity Mn-MOFs-based electrode material

Info

Publication number: CN113436910A
Application number: CN202110658568.2A
Authority: CN
Inventors: 温玉清; 刘燕红; 刘家宏; 尚伟
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-09-24

Abstract

A preparation method of a high-conductivity Mn-MOFs-based electrode material. Using carbon cloth which is ultrasonically washed by HCl, absolute ethyl alcohol and deionized water for 30min respectively and dried for 12 hours at the temperature of 60 ℃ as a substrate, and additionally preparing 1.9mmol of 1, 3, 5-benzenetricarboxylic acid, 2.5mmol of 50 percent manganese nitrate solution and 36mL of C₂H₅The mixed solution of OH is used as raw material solution. And (2) immersing the carbon cloth into the raw material liquid, ensuring that the carbon cloth is parallel to the liquid level of the raw material liquid, and putting the carbon cloth into a reaction kettle to react for 2 hours at the temperature of 120 ℃ to obtain the Mn-MOFs electrode material taking the carbon cloth as the substrate. The electrode material does not use a conductive agent and a binder, and Mn-MOFs is directly attached to the surface of the flexible conductive substrate carbon cloth in one step by utilizing hydrothermal. And the in-situ growth of Mn-MOFs on the carbon cloth ensures the close contact of reactants and excellent charge transmission property, the obtained product has uniform growth and higher purity, and the method is simple to operate and easy to realize industrial application.

Description

Preparation method of high-conductivity Mn-MOFs-based electrode material

Technical Field

The invention belongs to the technical field of preparation of electrode materials of supercapacitors, and particularly relates to a preparation method of a high-conductivity Mn-MOFs/CC supercapacitor electrode material.

Background

The Super Capacitor (SC) has higher energy density than the traditional capacitor, higher power density than the battery, high charging and discharging efficiency and long cycle life, and greatly makes up the defects of the traditional capacitor and the battery. Therefore, the method has great potential application value in the fields of electrochemical energy storage such as energy power, mobile communication, aerospace and the like. Although research and development of SC electrode materials have made significant progress, the low specific surface area and porosity of currently-used electrode materials decrease the effective contact area of an electrode active component and an electrolyte, resulting in difficulty in increasing the energy density and power density of SC energy storage devices. Therefore, the development of high-performance and low-cost electrode materials is of great significance to the current SC research work.

The MOFs material has the unique advantages of high specific surface area, high porosity, adjustable structure, high exposure, uniformly dispersed active sites and the like, so that the MOFs can be directly applied to SC as an electrode material. Although researchers have produced various MOF-based supercapacitor materials, the conductivity of the materials is poor, and few reports have been made of the use of virgin manganese-based MOFs (Mn-MOFs) as electrodes for SCs. Therefore, the synthesis of the Mn-MOF electrode material based on high conductivity and the use of the Mn-MOF electrode material in SC are beneficial to promoting the development of the SC high performance electrode material. The invention adopts a simple hydrothermal technology to grow octahedral Mn-MOF nano structures on Carbon Cloth (CC) in situ, and uses the octahedral Mn-MOF nano structures as the anode to research the electrochemical performance of the material in SC by using a three-electrode system. The product obtained by the electrode material prepared by the method has the advantages of uniform growth, higher purity, excellent charge transfer property, simple operation, reduced use of binder and easy realization of industrial application.

Disclosure of Invention

The invention aims to provide a preparation method of a high-conductivity Mn-MOFs/CC supercapacitor electrode material.

The method comprises the following specific steps:

(1) selecting 1X 1cm²The carbon cloth is used as a substrate material, the carbon cloth is ultrasonically washed for 10-30 min by HCl, absolute ethyl alcohol and deionized water respectively, and the carbon cloth is dried for 8-12 hours at the temperature of 30-60 ℃ for later use.

(2) 0.5-2 mmol of 1, 3, 5-benzenetricarboxylic acid, 1-4 mmol of 50% manganese nitrate solution and 20-36 mL of C₂H₅Putting OH into a reaction kettle, dissolving by magnetic stirring to obtain uniformly mixed raw material liquid, putting the carbon cloth obtained in the step (1) into the reaction kettle to ensure that the liquid level of the carbon cloth is parallel to that of the raw material liquid, and then, putting the carbon cloth into the reaction kettle to be uniformly mixed with the raw material liquidAnd (2) putting the carbon cloth into a blast drying oven, reacting for 1-4 h at 100-140 ℃, finally taking out the carbon cloth, washing the carbon cloth with ethanol and deionized water for several times, putting the carbon cloth into a vacuum drying oven, and drying for 8-12 h at 50-80 ℃ to obtain the Mn-MOF/CC electrode material.

The method disclosed by the invention is simple to operate, the electrode material Mn-MOF is grown in situ on the surface of the carbon cloth by a hydrothermal method, the close contact of reactants and good charge transmission property are ensured by the in-situ growth on the carbon cloth, the obtained product is uniform in growth, the raw material source is wide, the manufacturing cost is low, the preparation method is simple, and the use of a binder is reduced.

Drawings

FIG. 1 is an SEM image of pure carbon cloth and an SEM image of Mn-MOF/CC electrode material prepared by an embodiment of the invention

FIG. 2 shows CV tests of Mn-MOF/CC electrode materials prepared by the embodiment of the invention under different scanning rates.

FIG. 3 shows GCD tests of Mn-MOF/CC electrode materials prepared by the embodiment of the invention under different current densities.

FIG. 4 shows the resistance test of Mn-MOF/CC electrode material prepared by the embodiment of the invention.

Detailed Description

Example (b):

(1) selecting 1X 1cm²Carbon Cloth (CC) is used as a substrate material, the carbon cloth is ultrasonically washed for 30min by HCl, absolute ethyl alcohol and deionized water respectively, and is dried for 12 hours at the temperature of 60 ℃ for standby

(2) 1.9mmol of 1, 3, 5-benzenetricarboxylic acid, 2.5mmol of 50% manganese nitrate solution, 36mL of C₂H₅And (2) putting OH into a reaction kettle, magnetically stirring and dissolving to obtain a uniformly mixed raw material solution, putting the carbon cloth obtained in the step (1) into the reaction kettle, ensuring that the carbon cloth is parallel to the liquid level of the raw material solution, then putting the carbon cloth into a blast drying box, reacting for 2 hours at 120 ℃, finally taking out the carbon cloth, washing the carbon cloth with ethanol and deionized water for several times, putting the carbon cloth into a vacuum drying box, and drying for 12 hours at 60 ℃ to obtain the Mn-MOF/CC electrode material.

The characterization of the Mn-MOF/CC prepared in this example by SEM of FIG. 1 shows that Mn-MOF is uniformly distributed and very dense on the carbon cloth, which can provide more active sites and surface area for electrochemical reaction. FIG. 2 is a CV test of the Mn-MOF/CC electrode material prepared in the embodiment under different sweep rates, and it can be seen from the graph that the response current increases linearly with the increase of the sweep rate, and the CV curve substantially maintains its original shape, which indicates that the electrode material has good capacitive and electrochemical reversibility. And the samples showed distinct peaks at 0.6V and 0.9V, indicating that redox reactions occurred during the anode and cathode potential scans. Fig. 3 shows the GCD test of the Mn-MOF/CC electrode material prepared in this example at different current densities, from which two distinct plateaus can be seen, which belong to the GCD curve of the cell type, and the redox reaction occurs in accordance with the CV results. The GCD curves in these figures are asymmetric and plateaus appear, indicating good pseudocapacitance characteristics. FIG. 4 is the electrochemical AC impedance curve of the Mn-MOF/CC electrode material prepared in this example, and it can be seen that the material has small transfer resistance during charge transfer.

Claims

1. A preparation method of a high-conductivity Mn-MOFs/CC supercapacitor electrode material is characterized by comprising the following specific steps:

(1) selecting 1X 1cm²The method comprises the following steps of (1) taking carbon cloth as a substrate material, ultrasonically washing the carbon cloth for 10-30 minutes by using HCl, absolute ethyl alcohol and deionized water respectively, and drying the carbon cloth for 8-12 hours at the temperature of 30-60 ℃ for later use;

(2) 0.5-2 mmol of 1, 3, 5-benzenetricarboxylic acid, 1-4 mmol of 50% manganese nitrate solution and 20-36 mL of C₂H₅Putting OH into a reaction kettle, magnetically stirring and dissolving to obtain a uniformly mixed raw material solution, putting the carbon cloth obtained in the step (1) into the reaction kettle, ensuring that the carbon cloth is parallel to the liquid level of the raw material solution, then putting the carbon cloth into a blast drying box, reacting for 1-4 hours at 100-140 ℃, finally taking out the carbon cloth, washing the carbon cloth with ethanol and deionized water for several times, putting the carbon cloth into a vacuum drying box, and drying for 8-12 hours at 50-80 ℃ to obtain the Mn-MOF/CC electrode material;

the 1, 3, 5-benzene tricarboxylic acid, the manganese nitrate and the absolute ethyl alcohol are all chemically pure and have the purity above.