CN115440509A - Preparation method of array type nickel-cobalt-nitrogen nanosheet/carbon felt for supercapacitor - Google Patents

Abstract

"A method for preparing array-type nickel-cobalt-nitrogen nanosheets/carbon felts for supercapacitors" belongs to the field of supercapacitor electrode materials, and the nanomaterials are sheet-like array structures grown on the surface of carbon felts. The array-type nickel-cobalt-nitrogen nanomaterial adopts the synthesis method of electrodeposition and ammonia nitriding, with pretreated carbon felt as the substrate, nickel chloride hexahydrate as the nickel source, cobalt chloride hexahydrate as the cobalt source, ammonia Gas is used as the nitrogen source, and the prepared nickel-cobalt-nitrogen nanosheets grow uniformly and vertically on the surface of the carbon felt. It is directly used as an electrode of a supercapacitor, and the three-electrode test shows that when the current density is 3A/m ² , its specific capacity is 21710F/m ² . The array-type nickel-cobalt-nitrogen nanosheet/carbon felt prepared by the invention has the characteristics of high specific capacity, simple preparation method, low cost and the like.

Description

A preparation method of array-type nickel-cobalt-nitrogen nanosheet/carbon felt for supercapacitor

technical field

The invention discloses a method for preparing an array-type nickel-cobalt-nitrogen nanosheet/carbon felt for a supercapacitor, belonging to the field of supercapacitor electrode materials.

technical background

With the massive consumption of traditional energy (such as oil, coal and natural gas, etc.) New energy storage devices. As a new type of energy storage device, supercapacitor has the characteristics of high power density, short charge and discharge time, long service life, wide temperature range and safety, and is widely used in smart grid systems, industrial energy-saving systems, and power supply systems. and many electronic devices. Therefore, supercapacitors have become one of the hot research directions of new energy storage devices. The electrode material is one of the main factors affecting the performance of supercapacitors.

Due to the high theoretical specific capacity of transition metal compounds, it is one of the hot research directions of pseudocapacitive electrode materials. Compared with transition metal oxides, metal nitrides have higher conductivity, which is more conducive to improving the energy density of supercapacitors while ensuring a higher power density, but the conductivity of existing metal nitrides is still Difficult to meet requirements. In order to improve the conductivity of transition metal nitrides, most of the existing literature is composited with carbon, most of which are based on single metal nitride/carbon composites, while there are few reports on double metal nitrides/carbon composites, and the prepared composites The material is mainly in powder form. In addition, although both carbon nanotubes and graphene can improve their electrical conductivity, the cost is relatively high, which is not conducive to commercial application. On the contrary, commercial graphitic carbon felt not only has high electrical conductivity, but also has a large specific surface area, and the price is relatively low, especially the self-supporting array type NiCoN/carbon felt composite material reported less.

Contents of the invention

The invention provides a method with low cost, simple preparation process, short period and easy operation, and successfully prepares a self-supporting array-type nickel-cobalt-nitrogen nanosheet/carbon felt composite by using the synthesis method of electrodeposition and ammonia gas nitriding , when it is directly used as an electrode of a supercapacitor, it exhibits good electrochemical performance.

The preparation method of the self-supporting array type nickel-cobalt-nitrogen nanosheet/carbon felt used for supercapacitor provided by the invention comprises the following steps:

a) Put the 3mm thick carbon felt into the plasma cleaning machine, set the power to 80W under the condition of air atmosphere, after processing for 5 minutes, cut the carbon felt into a shape with a length and width of 2*1cm for later use;

b) Add deionized water, nickel chloride hexahydrate, cobalt chloride hexahydrate and thiourea to a 100mL beaker successively, stir for 10min and set aside;

c) Place the beaker with the precursor solution in b in a water bath at a certain temperature, and connect the cut carbon felt in a to the working electrode, and use the foil and saturated calomel electrode as the counter electrode and reference respectively The electrodes, which together form three electrodes, are put into the precursor solution, and then deposited under a specific voltage for a period of time, then the carbon felt is taken out and washed with water and dried;

d) Place the dried carbon felt in c in a porcelain boat, transfer it to a tube furnace, heat up to a predetermined temperature, and heat it for a period of time under an ammonia atmosphere, then cool it down to room temperature with the furnace. Obtain self-supporting array-type nickel-cobalt-nitrogen nanosheets/carbon felt composites.

e) The above self-supporting array-type nickel-cobalt-nitrogen nanosheet/carbon felt composite material is directly used as an electrode in a supercapacitor.

The additions of deionized water, nickel chloride hexahydrate, cobalt chloride hexahydrate and thiourea in the step b) are respectively 80ml, 0.08mmol, 0.16mmol and 1.6mmol;

Step c) Deposit for 9 minutes at a water bath temperature of 40°C and a deposition voltage of -0.8V;

In the step d), under an ammonia atmosphere, the heating rate is 8°C/min from room temperature to 420°C, and the temperature is kept for 3h;

In the step e) in the supercapacitor three-electrode performance test, the electrolyte is 1mol/L sodium hydroxide solution, and when the current density is 3A/m2, the specific capacity of the electrode is 21710F/ ^m2 .

Compared with other methods for preparing nickel-cobalt-nitrogen/carbon composite materials, this method firstly prepares array-type nickel-cobalt-nitrogen nanosheets on the surface of commercial carbon felt. In addition, the preparation process is simple, and the raw materials are cheap and easy to obtain, which is suitable for large-scale production. , which reduces the production cost and shortens the production cycle; and it can be directly used as an electrode of a supercapacitor, and has a good specific capacity.

2θ＝10-80°)测定所制备材料的结构。采用Hitachi S-4800扫描电子显微镜观察所制备材料的表面形貌。采用电化学工作站(CHI 660E)进行超电性能的测试。Bruker Advance D8 X-ray powder diffractometer (Cu Kα radiation,

2θ=10-80°) to determine the structure of the prepared material. A Hitachi S-4800 scanning electron microscope was used to observe the surface morphology of the prepared materials. Electrochemical workstation (CHI 660E) was used to test the superelectric performance.

As shown in Fig. 1 curve 1, when the addition of nickel chloride hexahydrate is 0.24mmol, and the addition of cobalt chloride hexahydrate is 0, the prepared material is nickel nitride/carbon felt composite material (JCPDS card No.10- 0280); As can be seen from Fig. 1 curve 3, when the add-on of nickel chloride hexahydrate is 0, when the add-on of cobalt chloride hexahydrate is 0.24mmol, the material prepared is cobalt nitride/carbon felt composite material (JCPDS card No. .06-0647); As shown in Fig. 1 curve 2 and Fig. 2, when the add-on of nickel chloride hexahydrate is 0.08mmol, when the add-on of cobalt chloride hexahydrate is 0.16mmol, the material prepared is nickel cobalt nitrogen/carbon Felt composite. It can be seen from Fig. 3 that the obtained nickel-cobalt-nitrogen is mainly a sheet structure, which grows on the surface of the carbon felt in an array state, but the size of the nanosheets is different. It can be seen from Figure 4 that when the self-supporting array-type nickel-cobalt-nitrogen nanosheet/carbon felt composite is used as a supercapacitor electrode for cyclic voltammetry test, as the scan rate increases from 2mV/s to 20mV/s, the area of the CV curve It also increases, and the peak position also shifts. It can be seen from Figure 5 that when the current density is 3A/m ² , the specific capacity of the electrode is 21710F/m ² .

Description of drawings

Fig. 1 is respectively when the molar ratio of nickel chloride hexahydrate and cobalt chloride hexahydrate is 0.24/0 (1), 0.08/0.16 (2) and 0/0.24 (3), the X-ray diffraction pattern of the product obtained.

Fig. 2 is the general figure of X-ray diffraction of Fig. 1 three products

Figure 3 is a scanning electron micrograph of the product.

Fig. 4 is a CV curve diagram of the self-supporting array-type nickel-cobalt-nitrogen nanosheet/carbon felt composite material prepared in the embodiment.

Fig. 5 is a charge-discharge curve diagram of the self-supporting array-type nickel-cobalt-nitrogen nanosheet/carbon felt composite material prepared in the embodiment.

detailed description

1. Put a carbon felt with a length of 10cm, a width of 5cm, and a thickness of 3mm into the plasma cleaning machine, set the power to 80W, and take it out after 5 minutes of treatment in the air atmosphere, and cut it into a shape with a length and width of 2*1cm spare;

2. Add 80ml deionized water, 0.08mmol nickel chloride hexahydrate, 0.16mmol cobalt chloride hexahydrate and 1.6mmol thiourea to a 100mL beaker successively, stir for 10 minutes and set aside;

3. Place the beaker containing 80ml of precursor solution in a water bath at 40°C, and at the same time connect the cut carbon felt to the working electrode, and connect the foil and saturated calomel electrode to the counter electrode and reference electrode circuit respectively In the process, the three electrodes are formed together, and then the three electrodes are put into the precursor solution, and then deposited at a voltage of -0.8V for 8 minutes, and then the carbon felt is taken out and washed with water and dried;

4. Place the dried carbon felt in a porcelain boat and transfer it to a tube furnace. Under an ammonia atmosphere, heat up at a rate of 8°C/min from room temperature to 420°C. After cooling down to room temperature, a self-supporting array-type nickel-cobalt-nitrogen nanosheet/carbon felt composite material can be obtained (see Figures 1, 2 and 3).

Claims (4)

1. A method for preparing an array type nickel-cobalt-nitrogen nanosheet/carbon felt for a supercapacitor, comprising the following steps: a) Put the 3mm thick carbon felt into the plasma cleaning machine, set the power to 80W under the condition of air atmosphere, after processing for 5 minutes, cut the carbon felt into a shape with a length and width of 2*1cm for later use; b) In a 100mL beaker, successively add deionized water, nickel chloride hexahydrate, cobalt chloride hexahydrate and thiourea, and then stir for 10 minutes before use; c) Place the beaker with the precursor solution in b in a water bath at a certain temperature, and connect the cut carbon felt in a to the working electrode, and use the foil and saturated calomel electrode as the counter electrode and reference respectively The electrodes, which together form three electrodes, are put into the precursor solution, and then deposited under a specific voltage for a period of time, then the carbon felt is taken out and washed with water and dried; d) Transfer the carbon felt dried in c to a porcelain boat, place it in a tube furnace, heat up to a predetermined temperature, and heat it for a period of time under an ammonia atmosphere, then cool it down to room temperature with the furnace, and then Obtain self-supporting array-type nickel-cobalt-nitrogen nanosheets/carbon felt composites. 2. according to claim 1, the preparation method of a kind of supercapacitor array type nickel-cobalt-nitrogen nano sheet/carbon felt is characterized in that, in the described step b), deionized water, nickel chloride hexahydrate, chlorine hexahydrate The amount of cobalt chloride and thiourea added is 80ml, 0.08mmol, 0.16mmol and 1.6mmol respectively. 3. according to claim 1, a kind of preparation method of array-type nickel-cobalt-nitrogen nanosheet/carbon felt for supercapacitor, it is characterized in that, described step c) is at 40 ℃ water bath temperature, when deposition voltage is-0.8V , deposition for 9min. 4. the preparation method of a kind of supercapacitor array type nickel-cobalt-nitrogen nanosheet/carbon felt according to claim 1, is characterized in that, in described step d), under ammonia gas atmosphere, with 8 ℃/min heating rate From room temperature to 420°C, and heat preservation for 3h.

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