Preparation of terbium metal organic complex and its application in supercapacitor

Abstract

The application discloses a preparation method of a terbium metal organic complex and application of the terbium metal organic complex in supercapacitors. The terbium metal organic complex is prepared by taking terbium chloride hexahydrate and triphenylphosphine as raw materials, adding the two into an alcohol-water mixed solution, stirring for 4 hours at 50 DEG C, and then drying and vacuum drying. The supercapacitor prepared by using the terbium metal organic complex has the characteristics of high specific capacity and good cycle performance, and thus has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of battery material preparation, and particularly relates to a preparation of a terbium-based metal organic complex and application thereof in supercapacitors. BACKGROUND

[0002] Since the first commercial supercapacitor was introduced in 1971, supercapacitors have entered the market operation stage. As a kind of energy storage device, supercapacitors (SCs) have attracted much attention due to their superior specific power and long-term cycling performance. According to the working principle, supercapacitors can be divided into pseudo-capacitive supercapacitors and double-layer supercapacitors. The former stores energy based on reversible Faraday reactions between the electrode and the electrolyte, while the current commercial supercapacitors are mainly based on the double-layer mechanism, which mostly relies on the electrostatic accumulation of ions with opposite charges on the electrode and electrolyte surface to store energy. SUMMARY

[0003] The application aims to provide a preparation of a terbium-based metal organic complex and application thereof in supercapacitors.

[0004] To achieve the above-mentioned purpose, the application adopts the following technical solutions:

[0005] A preparation method of a terbium-based metal organic complex, which comprises the following steps: adding terbium chloride hexahydrate and triphenylphosphine into an ethanol-water mixed solution, stirring at 50℃ for 4 hours, then removing the solvent by evaporation in a fume hood for two days, and vacuum drying to obtain the terbium-based metal organic complex.

[0006] Further, the mass ratio of terbium chloride hexahydrate to triphenylphosphine is 1-2:1.

[0007] Further, the volume ratio of anhydrous ethanol to water in the ethanol-water mixed solution is 2:1.

[0008] The obtained terbium-based metal organic complex can be used to prepare supercapacitors. Specifically, the terbium-based metal organic complex is mixed and ground with acetylene black and polyvinylidene fluoride at a mass ratio of 7:2:1, and then uniformly coated on a foamed nickel as a working electrode. A mercury / mercury oxide electrode and a platinum electrode are used as a reference electrode and a counter electrode, respectively, and a 6M KOH solution is used as an electrolyte.

[0009] The supercapacitor prepared by the terbium-based metal organic complex has high specific capacity and long cycle stability. The specific capacity is 1866 F / g at a current density of 2 A / g, and the capacity retention rate is 81.02% after 30,000 cycles. The performance is superior to that of the related materials reported in the prior art (see Table 1). Moreover, the preparation process is simple, the cost is low, the reproducibility is good, and the supercapacitor has a good development prospect.

[0010] Table 1 Comparison of electrochemical performance of the complex obtained in the present application with that of the prior reported materials

[0011] BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 XRD spectrum of the terbium-based metal organic complex prepared in the example.

[0013] Figure 2 Scanning electron microscope image of the terbium-based metal organic complex prepared in the example.

[0014] Figure 3 Transmission electron microscope image of the terbium-based metal organic complex prepared in the example.

[0015] Figure 4 Elemental mapping of the terbium-based metal organic complex prepared in the example.

[0016] Figure 5 XPS spectrum of the terbium-based metal organic complex prepared in the example.

[0017] Figure 6 Charge-discharge curve of the supercapacitor prepared using the terbium-based metal organic complex obtained in the example under different current density conditions.

[0018] Figure 7 Cycling performance stability test results of the supercapacitor prepared using the terbium-based metal organic complex obtained in the example. DETAILED DESCRIPTION

[0019] In order to make the content of the present application more convenient to understand, the technical solutions described in the present application will be further described below in combination with specific embodiments, but the present application is not limited thereto. EXAMPLE

[0020] 1.12 grams of terbium chloride hexahydrate and 1.57 grams of triphenylphosphine were added to a mixed solution of 20 mL of ethanol and 10 mL of water, stirred at 50°C for 4 hours, then volatilized in a fume hood for two days to remove the solvent, and then placed in a vacuum oven for drying to obtain Tb-(Ph)3P.

[0021] Figure 1 XRD spectrum of the obtained Tb-(Ph)3P. As can be seen from the figure, the obtained Tb-(Ph)3P has good crystallinity.

[0022] Figure 2 Scanning electron microscope image of the obtained Tb-(Ph)3P. As can be seen from the figure, the Tb-(Ph)3P is composed of nanosheets, and the thickness thereof is about 60-70 nm.

[0023] Figure 3 It is a transmission electron microscope image of the obtained Tb-(Ph)3P. It can be seen from the figure that the Tb-(Ph)3P is a bulk material formed by nanosheets stacked together.

[0024] Figure 4 It is an element distribution map of the obtained Tb-(Ph)3P. It can be seen from the figure that the elements of Tb, P and C are uniformly distributed, and the content of the P element is greater than that of the Tb element.

[0025] Figure 5 It is an XPS spectrum of the obtained Tb-(Ph)3P. It can be seen from the figure that the Tb-(Ph)3P contains Tb-O, C-P, C-C and Tb-P bonds, indicating that the complex is successfully synthesized.

[0026] Application Example

[0027] The obtained Tb-(Ph)3P is mixed and ground with acetylene black and polyvinylidene fluoride at a mass ratio of 7:2:1, and then uniformly coated on a foamed nickel as a working electrode. A mercury / mercury oxide electrode and a platinum electrode are used as a reference electrode and a counter electrode respectively, and a 6M KOH solution is used as an electrolyte to form a supercapacitor

[0028] Figure 6 It is an electrochemical performance test diagram of the prepared supercapacitor under different current density conditions. It can be seen from the figure that when the current density is 3, 5, 10 and 20 A·g -1 , the specific capacitance of the obtained supercapacitor can be 1700, 1650, 1366 and 1067 F·g -1 respectively, and when the current density is 2 A·g -1 , the specific capacitance is as high as 1866 F·g -1 .

[0029] Figure 7 It is a cycle performance stability test result diagram of the prepared supercapacitor. It can be seen from the figure that under the condition of a current density of 10 A·g -1 , the capacity retention rate of the obtained supercapacitor after 30,000 cycles is 81.02%.

[0030] The above only describes the preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the patent application of the present application shall be included in the scope of the present application.

Claims

1. Use of a terbium-based metal organic complex in the preparation of a supercapacitor, characterized in that: A terbium metal organic complex is mixed with acetylene black and polyvinylidene fluoride in a mass ratio of 7:2:1, ground and used as an electrode material for preparing a supercapacitor; The terbium metal organic complex is prepared by adding terbium chloride hexahydrate and triphenylphosphine into an ethanol-water mixed solution, stirring at 50 DEG C for 4 hours, then evaporating in a fume hood for two days to remove the solvent, and vacuum drying. The volume ratio of anhydrous ethanol to water in the ethanol-water mixed solution is 2:

1.

2. Use according to claim 1, characterized in that: The mass ratio of terbium chloride hexahydrate to triphenylphosphine used is 1-2:1.

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