阅读说明：本技术 硫掺杂三氧化二铋的制备方法、负极材料和超级电容器 (Preparation method of sulfur-doped bismuth trioxide, negative electrode material and supercapacitor ) 是由 张欣 高艳芳 李利军 鲍新 于 2020-12-29 设计创作，主要内容包括：本发明提供一种硫掺杂三氧化二铋的制备方法、负极材料和超级电容器。所述方法包括以下步骤：(1)称取预定量的五水合硝酸铋加入预定体积的醇溶剂中,然后在室温下搅拌30min；(2)将步骤(1)中所得的溶液转移至高压反应釜中,然后进行保温和离心处理,以获得白色沉淀；(3)将步骤(2)中所得的白色沉淀洗涤、彻底干燥后,充分研磨至细小粉末；(4)将步骤(3)中所得的粉末置于马弗炉中煅烧,以获得黄色三氧化二铋粉末；以及(5)将步骤(4)中所得的三氧化二铋粉末在硫粉存在的条件下进一步退火,以制得硫掺杂三氧化二铋。本发明的制备方法原料廉价易得、设备成本低、操作过程简单、耗时短,非常适合工业化生产的推广。(The invention provides a preparation method of sulfur-doped bismuth trioxide, a negative electrode material and a super capacitor. The method comprises the following steps: (1) weighing a predetermined amount of bismuth nitrate pentahydrate, adding the bismuth nitrate pentahydrate into an alcohol solvent with a predetermined volume, and stirring at room temperature for 30 min; (2) transferring the solution obtained in the step (1) into a high-pressure reaction kettle, and then carrying out heat preservation and centrifugation treatment to obtain white precipitate; (3) washing and completely drying the white precipitate obtained in the step (2), and fully grinding the white precipitate into fine powder; (4) calcining the powder obtained in the step (3) in a muffle furnace to obtain yellow bismuth trioxide powder; and (5) further annealing the bismuth trioxide powder obtained in the step (4) in the presence of sulfur powder to prepare the sulfur-doped bismuth trioxide. The preparation method has the advantages of cheap and easily-obtained raw materials, low equipment cost, simple operation process and short time consumption, and is very suitable for popularization of industrial production.)

1. Sulfur-doped Bi₂O₃The preparation method is characterized by comprising the following steps:

(1) weighing a predetermined amount of bismuth nitrate pentahydrate, adding the bismuth nitrate pentahydrate into an alcohol solvent with a predetermined volume, and stirring at room temperature for 30 min;

(2) transferring the solution obtained in the step (1) into a high-pressure reaction kettle, and then carrying out heat preservation and centrifugation treatment to obtain white precipitate;

(3) washing and completely drying the white precipitate obtained in the step (2), and fully grinding the white precipitate into fine powder;

(4) calcining the powder obtained in the step (3) in a muffle furnace to obtain yellow Bi₂O₃Powder; and

(5) bi obtained in the step (4)₂O₃Annealing the powder in the presence of sulfur powder to obtain sulfur-doped Bi₂O₃。

2. The sulfur-doped Bi of claim 1₂O₃Characterized in that the alcohol solvent comprises ethanol and ethylene glycol.

3. The sulfur-doped Bi of claim 2₂O₃The method of (2), wherein the predetermined amount is 0.458g, the predetermined volume is 21mL, and the volumes of the ethanol and the ethylene glycol are 14mL and 7mL, respectively.

4. The sulfur-doped Bi of claim 1₂O₃The preparation method of (2), wherein in the step (2), the temperature of the heat preservation is 0-200 ℃, and the time of the heat preservation is 6-12 h.

5. The sulfur-doped Bi of claim 1₂O₃Is characterized in that, in the step (4), the temperature of the calcination is 200-500 ℃.

6. The sulfur-doped Bi of claim 1₂O₃The production method of (4), wherein in the step (4), the calcination time is 0.5 to 2.0 hours.

7. The sulfur-doped Bi of claim 1₂O₃Is characterized in that, in the step (5), the annealing temperature is 200-600 ℃.

8. The sulfur-doped Bi of claim 1₂O₃The production method of (5), wherein in the step (5), the annealing time is 20 to 50 min.

9. A negative electrode material, characterized in that it is prepared by doping Bi with sulfur according to any one of claims 1 to 8₂O₃The sulfur-doped Bi prepared by the preparation method₂O₃。

10. An ultracapacitor, comprising a negative electrode made using the negative electrode material of claim 9.

Technical Field

The invention belongs to the field of capacitor electrode materials, and relates to a sulfur-doped bismuth trioxide (Bi) material₂O₃) The preparation method adopts a sulfur-doped bismuth trioxide negative electrode material and the super capacitor containing the negative electrode material.

Background

Super Capacitors (SC) are high-efficiency energy storage devices, and have a wide development prospect due to their advantages of high cycle stability, low maintenance cost, rapid charge and discharge, and the like. Currently, the important factor restricting the commercial application of SC is lower energy density, and the ideal solution is to increase the energy density as much as possible without sacrificing high power density and cycle life to meet the requirement of practical application. The key factor really determining the energy density of the super capacitor is the electrode material, so far, the research of the anode material has been carried out initially, the capacity of the anode material is far higher than that of the cathode material, and the existing commercial cathode material basically adopts activated carbon, and the theoretical capacity is lower due to the energy storage mechanism of the activated carbon. Therefore, developing a new cathode material that can match the higher specific volume of the anode material is the key to improving the performance of the whole device. The transition metal oxide material is another commonly used negative electrode material, and although the theoretical specific capacity of the transition metal oxide material is higher than that of a carbon material, the extreme easiness in structural collapse and low conductivity of the transition metal oxide material become main problems limiting the application of the material.

Therefore, an electrode having high specific capacity and good cycle stability is soughtMaterials have been one of the challenges facing researchers. Although carbon-based materials have been widely used in the market as the negative electrode of supercapacitors, low specific capacitance remains a major disadvantage, hindering further development of new high energy density energy storage devices. Bi₂O₃The material is a novel cathode material with satisfactory power density, energy density and cycle life, and can improve the performance of the whole device of the super capacitor. For Bi₂O₃The defects of low forbidden band width, low catalytic efficiency and the like can be overcome, and the electrochemical performance can be improved by a non-metal ion doping mode.

Disclosure of Invention

In order to achieve the purpose, the invention provides a novel cathode material with satisfactory power density, energy density and cycle life by means of mainly doping to manufacture the lattice defects of the electrode material and further improving the conductivity of the material, thereby improving the performance of the whole device of the super capacitor.

In a first aspect of the present invention, there is provided a sulfur-doped Bi₂O₃The method for preparing (1), the method comprising the steps of:

(1) weighing a predetermined amount of bismuth nitrate pentahydrate, adding the bismuth nitrate pentahydrate into an alcohol solvent with a predetermined volume, and stirring at room temperature for 30 min;

(2) transferring the solution obtained in the step (1) into a high-pressure reaction kettle, and then carrying out heat preservation and centrifugation treatment to obtain white precipitate;

(3) washing and completely drying the white precipitate obtained in the step (2), and fully grinding the white precipitate into fine powder;

(4) calcining the powder obtained in the step (3) in a muffle furnace to obtain yellow Bi₂O₃Powder; and

(5) bi obtained in the step (4)₂O₃Further annealing the powder in the presence of sulfur powder to produce sulfur-doped Bi₂O₃。

According to some embodiments of the first aspect of the present invention, the alcohol solvent comprises ethanol and ethylene glycol.

According to some embodiments of the first aspect of the present invention, the predetermined amount is 0.458g, the predetermined volume is 21mL, and the volumes of the ethanol and the ethylene glycol are 14mL and 7mL, respectively.

According to some embodiments of the first aspect of the present invention, in the step (2), the temperature of the incubation is 0 to 200 ℃, and the time of the incubation is 6 to 12 hours.

According to some embodiments of the first aspect of the present invention, in step (4), the temperature of the calcination is 200-500 ℃.

According to some embodiments of the first aspect of the present invention, in step (4), the calcination is for a time period of 0.5 to 2.0 h.

According to some embodiments of the first aspect of the present invention, in step (5), the temperature of the annealing is 200-600 ℃.

According to some embodiments of the first aspect of the present invention, in step (5), the annealing time is 20 to 50 min.

In a second aspect of the present invention, there is provided a negative electrode material doped with Bi by the above-mentioned sulfur₂O₃The sulfur-doped Bi prepared by the preparation method₂O₃。

In a third aspect of the present invention, there is provided an ultracapacitor comprising a negative electrode made using the negative electrode material described above.

Compared with the prior art, the invention has the beneficial effects that:

(a) the novel sulfur-doped bismuth trioxide electrode with the nano coral-shaped structure is synthesized by a simple hydrothermal and calcining method, and the prepared electrode shows excellent capacitance performance and cycling stability;

(b) the preparation method has the advantages of cheap and easily-obtained raw materials, low equipment cost, simple operation process and short time consumption, and is very suitable for industrial production and popularization.

Drawings

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings and examples. In the drawings, like reference numerals are used to refer to like parts unless otherwise specified. Wherein:

FIGS. 1(a) to (f) are Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) views of electrode materials prepared according to examples 1 to 3 of the present invention, wherein (a) is a Scanning Electron Microscope (SEM) view of Bi-0S, (b) is an SEM view of Bi-25S, and (c) to (f) are elemental energy dispersive scanning analysis (EDS-Mapping) views of Bi-25S;

FIG. 2 is a Cyclic Voltammetry (CV) curve of electrode materials prepared according to examples 1 to 3 of the present invention;

FIG. 3 is a constant current charge-discharge (GCD) curve of electrode materials prepared according to examples 1 to 3 of the present invention;

fig. 4 is a graph of mass specific capacitance and coulombic efficiency for electrode materials prepared according to examples 1 to 3 of the present invention.

Detailed Description

The technical solution of the present invention is further described below by means of specific examples.

The raw materials used in the examples of the present invention are all those commonly used in the art, and the methods used in the examples are all those conventional in the art, unless otherwise specified.

A super capacitor electrode material is prepared by the following steps:

example 1:

(1) adding 0.458g of bismuth nitrate pentahydrate into 21mL of solvent (the volumes of ethanol and ethylene glycol are 14mL and 7mL respectively), and stirring for 30min at room temperature;

(2) the resulting solution was transferred to a 100mL reaction kettle and incubated at 160 ℃ for 8h in an electrically heated forced air oven.

(3) Cooling and centrifuging to obtain white precipitate, alternately washing the precipitate with deionized water and anhydrous ethanol for three times, vacuum drying at 80 deg.C for 12 hr, and grinding the precipitate to fine powder;

(4) the powder is calcined in a muffle furnace at 300 ℃ for 1h, so that yellow Bi is obtained₂O₃Powder, marked Bi-0S.

Example 2:

(1) adding 0.458g of bismuth nitrate pentahydrate into 21mL of solvent (the volumes of ethanol and ethylene glycol are 14mL and 7mL respectively), and stirring for 30min at room temperature;

(2) the resulting solution was transferred to a 100mL reaction kettle and incubated at 160 ℃ for 8h in an electrically heated forced air oven.

(3) Cooling and centrifuging to obtain white precipitate, alternately washing the precipitate with deionized water and anhydrous ethanol for three times, vacuum drying at 80 deg.C for 12 hr, and grinding the precipitate to fine powder;

(4) the powder is calcined in a muffle furnace at 300 ℃ for 1h, so that yellow Bi is obtained₂O₃And (3) powder.

(5) Adding Bi₂O₃The powder was further annealed at 400 ℃ for 30min in the presence of 0.025g of sulfur powder to form S-doped Bi₂O₃And is marked as Bi-25S.

Example 3:

(1) adding 0.458g of bismuth nitrate pentahydrate into 21mL of solvent (the volumes of ethanol and ethylene glycol are 14mL and 7mL respectively), and stirring for 30min at room temperature;

(2) the resulting solution was transferred to a 100mL reaction kettle and incubated at 160 ℃ for 8h in an electrically heated forced air oven.

(3) Cooling and centrifuging to obtain white precipitate, alternately washing the precipitate with deionized water and anhydrous ethanol for three times, vacuum drying at 80 deg.C for 12 hr, and grinding the precipitate to fine powder;

(4) the powder is calcined in a muffle furnace at 300 ℃ for 1h, so that yellow Bi is obtained₂O₃And (3) powder.

(5) Adding Bi₂O₃The powder was further annealed at 400 ℃ for 30min in the presence of 0.050g of sulfur powder to form sulfur-doped Bi₂O₃And is marked as Bi-50S.

Scanning Electron Microscope (SEM) images and Transmission Electron Microscope (TEM) images of the above Bi-0S and Bi-25S materials are shown in FIG. 1, respectively. In fig. 1: (a) scanning Electron Microscope (SEM) picture of Bi-0S, (b) SEM picture of Bi-25S, and (c) - (f) EDS-Mapping (EDS-Mapping) picture of Bi-25S.

From the SEM images in fig. 1, it can be seen that the electrode materials prepared by examples 1 and 2 of the present inventionIs in a nano coral shape, and the doping of sulfur does not cause the change of the structure. Doping S with Bi₂O₃Further study of the Mapping images revealed that Bi, O and S are present in the sample at the same time.

Then, the electrochemical properties of the above-mentioned three materials Bi-0S, Bi-25S and Bi-50S were investigated by using two methods of cyclic voltammetry and constant current charging and discharging, respectively, and the results are shown in FIGS. 2 and 3. FIG. 2 shows Bi-0S and Bi-25S at 3 mV. multidot.s^-1CV curve at sweep speed. The CV analysis shows that S is doped with Bi₂O₃Electrode display ratio Bi₂O₃Much higher current density of the electrode, which indicates that Bi is greatly increased due to sulfur doping₂O₃The pseudocapacitance performance of (a).

In FIG. 3, three electrode materials Bi-0S, Bi-25S and Bi-50S are shown at 1A · g^-1And (4) constant current charge and discharge curves tested under the current intensity. By comparing the constant current charge and discharge curves of the three electrode materials, the longest discharge time of Bi-25S can be determined, which indicates the highest capacitance.

FIG. 4 shows that Bi-25S is at 10A · g^-1And (4) circulating 4000 circles of a mass specific capacitance and coulombic efficiency graph under the current density. The cycle life test of the loop cycle test is carried out, and the embedded graph is a GCD curve of 1-5 loops and 3995-4000 loop cycles. After 4000 cycles, the Bi-25S material was initially 892.5 Fg^-1Attenuation to 535.5F g^-1The capacity retention rate and the coulombic efficiency can respectively reach 60% and 99.9%, which shows that the material has excellent cycle stability.

In example 1, the capacitance of undoped bismuth trioxide was 697.3 Fg^-1(ii) a In examples 2 and 3, Bi was doped with sulfur₂O₃As the electrode material, the super capacitance value is respectively raised to 927.0F g^-1And 744. F.g^-1. Therefore, the capacitance value in embodiment 2 is the largest, that is, it is preferable to use the Bi-25S material as the negative electrode material.

In conclusion, the electrode material prepared by the invention shows excellent super-capacitor performance. These properties are all the products of the nano coral-like structure prepared by the process parameters of the invention.

The preparation method has the advantages of cheap and easily-obtained raw materials, low equipment cost, simple operation process and short time consumption, and is very suitable for popularization of industrial production.

The technical scope of the present invention is not limited to the above description, and those skilled in the art can make various changes and modifications to the above-described embodiments without departing from the technical spirit of the present invention, and these changes and modifications all fall into the protective scope of the present invention.