CN103280339A - Method for preparing cerium oxide electrode of supercapacitor - Google Patents

Abstract

The invention relates to a method for preparing a cerium oxide electrode of a supercapacitor. The method comprises the following steps: a) mixing and stirring ceria powder of which the particle size is less than 1 mum, conductive agent and binder according to a certain proportion, wherein the content of the conductive agent is 10-20 wt% of the total mass of the mixture, and the content of the binder is 10-20 wt% of the total mass of the mixture; and b) coating the mixture on a current collector, and drying to obtain the cerium oxide electrode.

Description

A kind of preparation method for the cerium oxide electrode of supercapacitor

technical field

The invention relates to a method for preparing a cerium oxide electrode used in a supercapacitor, and belongs to the technical fields of chemical industry and material science and engineering. the

Background technique

Supercapacitor is an energy storage device with high energy density, high power and high cycle performance, and it has broad application prospects when used in conjunction with batteries. Now it has been widely used in aerospace, information technology and other fields that require instantaneous high-power discharge. Supercapacitors are divided into electric double layer capacitors and pseudocapacitors, among which pseudocapacitors have higher specific capacity than electric double layer capacitors, so they have more development potential. The electrode materials of pseudocapacitors are mainly transition metal oxides, such as ruthenium oxide, nickel oxide, cobalt oxide, and manganese oxide. At present, the more successful research on pseudocapacitive capacitors is the ruthenium oxide/H ₂ SO ₄ system, but the price of ruthenium oxide is high, and the H ₂ SO ₄ solution has high requirements on the electrode collector, which limits its wide application. Therefore, it is imperative to find low-cost, high-performance electrode materials. Ceria is a good electrode material, which has good electrochemical redox properties and low cost. The composite electrode material of ceria and graphene prepared by Li et al. has a specific capacity of 280Fg ^-1 . The application of the current collector also has a great impact on the performance of the electrode material. Nickel foam is an excellent electrode current collector material due to its porous three-dimensional structure and high specific surface area. In this patent, nickel foam is used as a current collector, and cerium oxide is used as an active material to prepare an electrode material with good electrochemical performance.

Contents of the invention

The object of the present invention is to provide a method for preparing a cerium oxide electrode for a supercapacitor, so as to obtain a supercapacitor electrode material with a high specific capacity. the

To achieve the above object, the present invention adopts the following technical solutions:

A preparation method for a cerium oxide electrode for a supercapacitor, comprising the following steps:

a) Mix and stir the ceria powder with a particle size of less than 1 μm, the conductive agent and the binder in a certain proportion, wherein the content of the conductive agent is 10-20wt% of the total mass of the mixture, and the content of the binder is 10% of the total mass of the mixture ~20wt%;

b) The mixture is coated on the current collector and dried to obtain a cerium oxide electrode.

The step b) may be: grind the mixture in step a), and then press it into a film with a thickness of 0.5-2 μm, and press the film on the current collector with a pressure of 10-50 MPa to obtain a cerium oxide electrode. the

The conductive agent is one or more of acetylene black, carbon nanotubes, and carbon nanospheres; the binder is polyvinylidene fluoride or polytetrafluoroethylene dissolved in dimethylacetamide or dimethylmethylene The solution formed in the sulfone organic solution; the current collector is nickel foam, stainless steel mesh, nickel sheet, titanium sheet or graphite sheet. the

Compared with the prior art, the present invention has the following prominent substantive features and remarkable progress:

a) The nickel foam current collector has a three-dimensional network structure, which increases the contact area between the active material and the electrolyte, thereby increasing the specific capacity of the electrode.

b) Compared with the electrode obtained by directly depositing a thin film on the current collector, the binding force between the electrode active material and the current collector prepared by the present invention is stronger, which is beneficial to prolong the service life of the electrode; the active material loading per unit area Larger mass is beneficial to increase the power of the electrode. the

Description of drawings

Fig. 1 is a cyclic voltammetry test chart of electrodes prepared in Example 1 and Example 2 of the present invention. the

Fig. 2 is a diagram of the cyclic voltammetry performance of the electrode tested in the alkaline electrolyte solution in Example 3 of the present invention. the

Fig. 3 is a diagram of the cyclic voltammetry performance of the electrode tested in a neutral electrolyte solution in Example 3 of the present invention. the

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the embodiments. the

Embodiment one

Mix cerium oxide powder with a particle size of less than 1 μm, acetylene black and polyvinylidene fluoride (PVDF) at a mass ratio of 80:10:10, place the mixture on a magnetic stirrer at room temperature and stir for 12 hours, and then spread it on a surface of size 1 ×2cm foamed nickel sheet, and then placed in a vacuum drying oven at 120 ° C for 12 hours to obtain a foamed nickel current collector cerium oxide electrode.

0.1M Na ₂ SO ₄ was used as the electrolyte solution, a saturated calomel electrode was used as the reference electrode, and platinum was used as the counter electrode to conduct cyclic voltammetry tests on the electrodes prepared above, as shown in Figure 1 . At a scan rate of 10 mV s ^-1 , the measured specific volume is 57 F g ^-1 .

Embodiment two

Mix cerium oxide powder with a particle size of less than 1 μm, acetylene black and polyvinylidene fluoride (PVDF) at a mass ratio of 80:10:10, place the mixture on a magnetic stirrer at room temperature and stir for 12 hours, and then spread it on a surface of size 1 ×1cm graphite sheet, and then dried in a vacuum oven at 120°C for 12h to finally obtain a graphite current collector cerium oxide electrode.

0.1M Na ₂ SO ₄ was used as the electrolyte solution, a saturated calomel electrode was used as the reference electrode, and platinum was used as the counter electrode to conduct cyclic voltammetry tests on the electrodes prepared above, as shown in Figure 1 . At a scan rate of 10 mV s ^-1 , the measured specific volume is 7 F g ^-1 .

Embodiment three

Mix cerium oxide powder with a particle size of less than 1 μm, acetylene black and polytetrafluoroethylene (PTFE) at a mass ratio of 70:15:15, grind the mixture and press it into a film with a thickness of about 2 μm, and press it after the film is dry. On the foamed nickel current collector, a cerium oxide electrode is obtained.

The prepared cerium oxide electrode was tested for electrochemical performance in alkaline electrolyte. In the cyclic voltammetry test, a saturated calomel electrode was used as the reference electrode, platinum was used as the counter electrode, the scanning rate was 5 mV s ^-1 , and the test voltage range was 0-0.4 V, as shown in Figure 2. Cyclic voltammetry tests were performed in 2M KOH, 2M NaOH, and 2M LiOH electrolytes, and the obtained specific volumes were 241 F g ^-1 , 152 F g ^-1 , and 87 F g ^{-1 ,} respectively.

The prepared cerium oxide electrode was tested for electrochemical performance in neutral electrolyte. In the cyclic voltammetry test, a saturated calomel electrode was used as the reference electrode, platinum was used as the counter electrode, the scanning rate was 5 mV s ^-1 , and the test voltage range was 0.5-0.9 V, as shown in Figure 3. The cyclic voltammetry test was carried out in 0.1M Na ₂ SO ₄ , 0.1M K ₂ SO ₄ , 0.1M (NH ₄ ) ₂ SO ₄ electrolytes, and the obtained specific volumes were 89 F g ^-1 , 61 F g ^-1 , 10 F g ^-1 .

Claims (3)

1. A preparation method for a cerium oxide electrode for supercapacitor, characterized in that, has the following steps: a) Mix and stir the ceria powder with a particle size of less than 1 μm, the conductive agent and the binder in a certain proportion, wherein the content of the conductive agent is 10-20wt% of the total mass of the mixture, and the content of the binder is 10% of the total mass of the mixture ~20wt%; b) The mixture is coated on the current collector and dried to obtain a cerium oxide electrode. 2. A method for preparing a cerium oxide electrode for a supercapacitor according to claim 1, characterized in that the step b) is: grinding the mixture in step a), and then pressing it into a thickness of 0.5-2 μm The film is pressed on the current collector with a pressure of 10-50 MPa to obtain a cerium oxide electrode. 3. a kind of preparation method for the cerium oxide electrode of supercapacitor according to claim 1 and 2, is characterized in that, described conductive agent is a kind of in acetylene black, carbon nanotube, carbon nano microsphere or several kinds; the binder is a solution formed by dissolving polyvinylidene fluoride or polytetrafluoroethylene in dimethylacetamide or dimethyl sulfoxide organic solution; the current collector is nickel foam, stainless steel mesh, nickel sheet, titanium flakes or graphite flakes.

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