Supercapacitor Materials and Their Preparation Methods

Abstract

The present invention discloses a supercapacitor material and a preparation method thereof, relating to the technical field of supercapacitor materials. The supercapacitor material includes a coating layer and a core disposed within the coating layer. The material of the coating layer includes RuO2, and the material of the core includes a nickel, copper, vanadium multi-metal composite oxide. The supercapacitor material proposed by the present invention can provide a richer redox reaction and generate more electroactive sites; the introduction of multi-metal atoms will lead to an increase in the defects of the microscopic crystal structure, and the unbalanced charge distribution can induce a local electric field, providing a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material. These synergistic effects among various components will improve the specific capacitance and cycling performance of the electrode material.

Description

Technical Field

[0001] The present invention relates to the technical field of supercapacitor materials, and particularly relates to a supercapacitor material and a preparation method thereof. Background Art

[0002] With the rapid consumption of fossil energy, exploring efficient and clean energy storage and conversion devices has become a major challenge for the sustainable development of human society. As a new type of high-efficiency energy storage device, supercapacitors have the advantages of large capacitance, fast charge and discharge speed, good cycle stability, and high power density. The most important component of a supercapacitor is the electrode material, so the key to the research of supercapacitors lies in the exploration and design of electrode materials. Commonly used supercapacitor materials mainly include carbon-based materials, metal oxide materials, and polymer conductive polymers, etc.

[0003] However, the existing supercapacitor materials have poor specific capacitance and cycle performance. Summary of the Invention

[0004] The main object of the present invention is to provide a supercapacitor material and a preparation method thereof, aiming to provide a supercapacitor material with good specific capacitance and cycle performance.

[0005] To achieve the above object, the present invention provides a supercapacitor material, including a coating layer and a core disposed inside the coating layer. The material of the coating layer includes RuO2, and the material of the core includes a nickel, copper, vanadium multi-metal composite oxide.

[0006] Optionally, the chemical formula of the nickel, copper, vanadium multi-metal composite oxide is Ni 0.5 Cu 0.5 V2O6; and / or,

[0007] The mass of the coating layer is 5% - 10% of the mass of the core.

[0008] The present invention further provides a preparation method of the above supercapacitor material, including the following steps:

[0009] S10. Dispersing vanadium pentoxide in water, adding a hydrogen peroxide solution to obtain a mixed solution;

[0010] S20. Performing a hydrothermal reaction on the mixed solution to obtain a solid-liquid mixture, separating the solid-liquid mixture, washing, vacuum drying, and calcining the obtained solid to obtain a vanadium pentoxide nano-precursor;

[0011] S30. Dissolving nickel nitrate hexahydrate, copper nitrate trihydrate, and a complexing agent in water, adding the vanadium pentoxide nano-precursor, heating and stirring in a water bath to obtain a wet gel, drying the wet gel, and performing secondary calcination to obtain a nickel, copper, vanadium multi-metal composite oxide;

[0012] S40. Dissolve ruthenium(III) chloride trihydrate in water, add the nickel, copper, vanadium multi-metal composite oxide, and after heating in a water bath, obtain the supercapacitor material through drying and calcination.

[0013] Optionally, in step S10,

[0014] The concentration of vanadium pentoxide in the mixed solution is 0.04 - 0.06 mol / L; and / or,

[0015] The volume of 30% hydrogen peroxide solution corresponding to each gram of vanadium pentoxide is 13 mL.

[0016] Optionally, in step S20,

[0017] The hydrothermal reaction temperature is 220 - 240 °C; and / or,

[0018] The hydrothermal reaction time is 10 - 15 h; and / or,

[0019] The vacuum drying temperature is 70 - 70 °C; and / or,

[0020] The vacuum drying time is 10 - 14 h; and / or,

[0021] The calcination temperature is 400 °C; and / or

[0022] The calcination time is 3 h; and / or

[0023] The heating rate during calcination is 5 °C / min.

[0024] Optionally, in step S20, the vanadium pentoxide nano-precursor is rod-shaped,

[0025] The cross-sectional diameter of the rod-shaped vanadium pentoxide nano-precursor is 20 - 1005 nm; and / or,

[0026] The length of the rod-shaped vanadium pentoxide nano-precursor is 0.5 - 3 μm.

[0027] Optionally, in step S30,

[0028] The volume of water corresponding to each gram of nickel nitrate hexahydrate is 50 mL; and / or,

[0029] The molar ratio of nickel nitrate hexahydrate, copper nitrate trihydrate, complexing agent, and vanadium pentoxide nano-precursor is 0.5:0.5:2:1; and / or,

[0030] The complexing agent includes glucose; and / or,

[0031] The water bath temperature is 80 °C; and / or

[0032] The water bath time is 2 to 4 h; and / or

[0033] The drying temperature is 60 to 80 °C; and / or,

[0034] The drying time is 40 to 50 h; and / or,

[0035] The first calcination temperature is 350 °C; and / or

[0036] The calcination time is 2 h; and / or

[0037] The second calcination temperature is 600 °C;

[0038] The calcination time is 3 to 5 h; and / or

[0039] The heating rate during calcination is 5 °C / min;

[0040] Optionally, in step S40, the mass ratio of ruthenium trichloride trihydrate, water and the nickel, copper, vanadium multi-metal composite oxide is (0.078 to 0.176):20:1.

[0041] Optionally, in step S40, the water bath temperature is 80 °C; and / or

[0042] The water bath time is 2 to 4 h; and / or

[0043] The drying temperature is 60 to 80 °C; and / or,

[0044] The drying time is 12 to 15 h.

[0045] Optionally, in step S40,

[0046] The heating rate during calcination is 5 °C / min; and / or,

[0047] The calcination temperature is 600 to 700 °C; and / or,

[0048] The calcination time is 3 to 5 h.

[0049] In the technical solution provided by the present invention, a supercapacitor material is proposed. The nickel, copper, and vanadium multi-metal composite oxide has excellent electrochemical performance. Its theoretical specific capacitance can reach 10 - 100 times that of carbon materials, and it has good stability. It is an ideal supercapacitor material. In addition, the preparation of multi-metal oxides by compounding two or more metal oxides can effectively improve the conductivity and stability of the electrode material, making metal oxides have a broader application prospect in the field of supercapacitors. Ruthenium dioxide has a relatively high conductivity and a very high theoretical specific capacitance (1580 F / g). The supercapacitor material proposed by the present invention can provide a richer redox reaction and generate more electroactive sites. The introduction of multi-metal atoms will lead to an increase in the number of microcrystalline structure defects. The unbalanced charge distribution can induce a local electric field, provide a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material. These synergistic effects among various components will improve the specific capacitance and cycling performance of the electrode material. Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained based on these drawings.

[0051] Figure 1 Ni prepared in Example 1 of the present invention 0.5 Cu 0.5 XRD patterns of the V2O6 / RuO2 material prepared in Example 1 of the present invention and the Ni 0.5 Cu 0.5 V2O6 material prepared in Comparative Example 3;

[0052] Figure 2 SEM image of the vanadium pentoxide nano-precursor prepared in Example 1 of the present invention;

[0053] Figure 3 Material Ni prepared in Comparative Example 3 of the present invention 0.5 Cu 0.5 SEM image of the V2O6 material;

[0054] Figure 4 Ni prepared in Example 1 of the present invention 0.5 Cu 0.5 SEM image of the V2O6 / RuO2 material;

[0055] Figure 5 Ni prepared in Example 1 of the present invention 0.5 Cu 0.5 First constant current charge-discharge curve of the V2O6 / RuO2 material prepared in Example 1 of the present invention.

[0056] The realization, functional features, and advantages of the present invention will be further described in conjunction with embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that satisfies both A and B at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0058] With the rapid consumption of fossil energy, exploring efficient and clean energy storage and conversion devices has become a major challenge for the sustainable development of human society. As a new type of high-efficiency energy storage device, supercapacitors have the advantages of large capacitance, fast charge and discharge speed, good cycle stability, and high power density. The most important component of a supercapacitor is the electrode material, so the key to the research of supercapacitors lies in the exploration and design of electrode materials. Commonly used supercapacitor materials mainly include carbon-based materials, metal oxide materials, and polymer conductive polymers. However, the existing supercapacitor materials have poor specific capacitance and cycle performance.

[0059] In view of this, the present invention proposes a supercapacitor material, aiming to provide a supercapacitor material with good specific capacitance and cycle performance.

[0060] The supercapacitor material proposed by the present invention includes a coating layer and a core disposed within the coating layer. The material of the coating layer includes RuO2, and the material of the core includes a nickel, copper, vanadium multi-metal composite oxide.

[0061] In the technical solution provided by the present invention, a supercapacitor material is proposed. The nickel, copper, and vanadium multi-metal composite oxide has excellent electrochemical performance. Its theoretical specific capacitance can reach 10-100 times that of carbon materials, and it has good stability. It is an ideal supercapacitor material. In addition, the preparation of multi-metal oxides by combining two or more metal oxides can effectively improve the conductivity and stability of the electrode material, enabling metal oxides to have a broader application prospect in the field of supercapacitors. Ruthenium dioxide has a relatively high conductivity and a very high theoretical specific capacitance (1580 F / g). The supercapacitor material proposed by the present invention can provide a richer redox reaction, generating more electroactive sites; the introduction of multi-metal atoms will lead to an increase in the defects of the microscopic crystal structure. The unbalanced charge distribution can induce a local electric field, providing a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material. These synergistic effects among various components will improve the specific capacitance and cycling performance of the electrode material.

[0062] The nickel, copper, and vanadium multi-metal composite oxide provides rich electroactive sites for the Faraday redox reaction. The introduction of multi-metal atoms will lead to an increase in the defects of the microscopic crystal structure. The unbalanced charge distribution can induce a local electric field, providing a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material; coating ruthenium dioxide on the surface of the nickel, copper, and vanadium composite oxide further increases the electroactive sites on the surface of the electrode material. The presence of ruthenium dioxide can also increase the electron conduction ability on the surface of the material. These synergistic effects among various components will improve the specific capacitance and cycling performance of the electrode material.

[0063] Preferably, the chemical formula of the nickel, copper, and vanadium multi-metal composite oxide is Ni 0.5 Cu 0.5 V2O6. Ni 0.5 Cu 0.5 V2O6 can provide a richer redox reaction, generating more electroactive sites; the introduction of multi-metal atoms will lead to an increase in the defects of the microscopic crystal structure. The unbalanced charge distribution can induce a local electric field, providing a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material. These synergistic effects among various components will improve the specific capacitance and cycling performance of the electrode material.

[0064] Preferably, the mass of the coating layer is 5% - 10% of the mass of the core. Under the above ratio, the supercapacitor material has good specific capacitance and cycling performance.

[0065] The present invention further proposes a preparation method of the supercapacitor material as described above, including the following steps:

[0066] S10. Disperse vanadium pentoxide in water, and add hydrogen peroxide solution to obtain a mixed solution.

[0067] Preferably, in step S10,

[0068] The concentration of vanadium pentoxide in the mixed solution is 0.04 - 0.06 mol / L; at the above concentration, it is beneficial to form vanadium pentoxide nano-precursors with uniform particles.

[0069] The volume of 30% hydrogen peroxide solution corresponding to each gram of the vanadium pentoxide is 13 mL. Specifically, this step can be operated by the following method: Disperse the vanadium pentoxide powder in deionized water, and dropwise add 30% hydrogen peroxide solution under stirring to obtain a mixed solution. Among them, 30% of the 30% hydrogen peroxide solution is the mass concentration, and the ratio of the mass of the vanadium pentoxide powder to the volume of the 30% hydrogen peroxide solution is 1 g:13 mL. Under the above ratio, it is beneficial to form vanadium pentoxide nano-precursors with uniform particles.

[0070] S20. Perform a hydrothermal reaction on the mixed solution to obtain a solid-liquid mixture, separate the solid and liquid of the solid-liquid mixture, and wash, vacuum dry, and calcine the obtained solid to obtain vanadium pentoxide nano-precursors.

[0071] Preferably, in step S20,

[0072] The hydrothermal reaction temperature is 220 - 240 °C; and / or,

[0073] The hydrothermal reaction time is 10 - 15 h; and / or,

[0074] The vacuum drying temperature is 70 - 70 °C; and / or,

[0075] The vacuum drying time is 10 - 14 h; and / or,

[0076] The calcination temperature is 400 °C; and / or

[0077] The calcination time is 3 h; and / or

[0078] The heating rate during calcination is 5 °C / min. Under the above conditions, it is beneficial to form vanadium pentoxide nano-precursors with uniform particles.

[0079] It can be understood that the above reaction conditions of the present invention can satisfy only one of them, or can satisfy multiple of them at the same time. As a preferred embodiment of the present invention, the above conditions are all satisfied, which is beneficial to form vanadium pentoxide nano-precursors with uniform particles.

[0080] Preferably, in step S20, the vanadium pentoxide nano-precursors are rod-shaped,

[0081] The cross-sectional diameter of the rod-shaped vanadium pentoxide nano-precursors is 20 - 1005 m; and / or,

[0082] The length of the rod-shaped vanadium pentoxide nano-precursor is 0.5 - 3 μm. It can be understood that the cross-sectional diameter of the rod-shaped vanadium pentoxide nano-precursor is the cross-sectional diameter of a vanadium pentoxide rod, and the length of the rod-shaped vanadium pentoxide nano-precursor is the circumferential length of a vanadium pentoxide rod. The above dimensions are conducive to the formation of a uniform nickel, copper, vanadium multi-metal composite oxide.

[0083] Specifically, the operation of this step is as follows: After stirring the mixed solution in a water bath at 60°C for 0.5 h, transfer it to a hydrothermal reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 220 - 240°C, and the hydrothermal reaction time is 10 - 15 h to obtain a solid-liquid mixture containing yellow flocculent vanadium pentoxide nano-precursors. Separate the solid and liquid of the solid-liquid mixture, wash the obtained solid with deionized water, dry it under vacuum, and calcine it in a muffle furnace at 400°C for 3 h to obtain vanadium pentoxide nano-precursors.

[0084] S30. Dissolve nickel nitrate hexahydrate, copper nitrate trihydrate and a complexing agent in water, add the vanadium pentoxide nano-precursor, heat and stir to obtain a wet gel, and dry and calcine the wet gel to obtain a nickel, copper, vanadium multi-metal composite oxide.

[0085] Preferably, in step S30,

[0086] The volume of water corresponding to each gram of nickel nitrate hexahydrate is 50 mL; and / or,

[0087] The molar ratio of nickel nitrate hexahydrate, copper nitrate trihydrate, complexing agent and vanadium pentoxide nano-precursor is 0.5:0.5:2:1; and / or,

[0088] The complexing agent includes glucose; and / or,

[0089] The water bath temperature is 80°C; and / or

[0090] The water bath time is 2 - 4 h; and / or

[0091] The drying temperature is 60 - 80°C; and / or,

[0092] The drying time is 40 - 50 h; and / or,

[0093] The first calcination temperature is 350°C; and / or

[0094] The calcination time is 2 h; and / or

[0095] The second calcination temperature is 600°C; and / or

[0096] The calcination time is 3 - 5 h; and / or

[0097] The heating rate during calcination is 5°C / min.

[0098] Under the above conditions, a nickel, copper, vanadium multi-metal composite oxide is prepared, which provides abundant electroactive sites for the Faraday redox reaction. The introduction of multi-metal atoms will lead to an increase in the number of microscopic crystal structure defects. The unbalanced charge distribution can induce a local electric field, providing a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material.

[0099] It can be understood that the above reaction conditions of the present invention can satisfy only one of them, or can satisfy multiple conditions at the same time. As a preferred embodiment of the present invention, the above conditions are all satisfied, which is beneficial to the formation of a nickel, copper, vanadium multi-metal composite oxide with uniform particles.

[0100] Specifically, the operation of this step is as follows: Dissolve nickel nitrate hexahydrate, copper nitrate trihydrate and a complexing agent in deionized water, add a vanadium pentoxide nano-precursor, and after fully mixing and dispersing evenly, continue to stir for 2-4 h under the condition of an 80 °C water bath to obtain a wet gel, transfer it to an oven for drying, the temperature is 60-80 °C, and the time is 40-50 h to obtain a dry gel. The obtained dry gel is first calcined in a muffle furnace at 350 °C for 2 h, cooled and ground, and then calcined in a muffle furnace at 600 °C for 3-5 h to obtain Ni 0.5 Cu 0.5 V2O6 composite oxide.

[0101] S40. Dissolve ruthenium trichloride trihydrate in water, and add the nickel, copper, vanadium multi-metal composite oxide. After heating in a water bath, a supercapacitor material is obtained through drying and calcination.

[0102] Preferably, in step S40, the mass ratio of ruthenium trichloride trihydrate, water and the nickel, copper, vanadium multi-metal composite oxide is (0.078-0.176):20:1.

[0103] Preferably,

[0104] The water bath temperature is 80 °C; and / or

[0105] The water bath time is 2-4 h; and / or

[0106] The drying temperature is 60-80 °C; and / or,

[0107] The drying time is 12-15 h.

[0108] Preferably, in step S40,

[0109] The heating rate during calcination is 5 °C / mi5; and / or,

[0110] The calcination temperature is 600-700 °C; and / or,

[0111] The calcination time is 3 to 5 h. Under the above conditions, it is beneficial to completely coat ruthenium dioxide outside the nickel, copper, and vanadium multi-metal composite oxide.

[0112] It can be understood that the above reaction conditions of the present invention can satisfy only one of them or multiple of them at the same time. As a preferred embodiment of the present invention, the above conditions are all satisfied, which is beneficial to form a supercapacitor material with uniform particles.

[0113] Specifically, the operation of this step is as follows: Dissolve ruthenium trichloride trihydrate in deionized water, and add Ni 0.5 Cu 0.5 V2O6 composite oxide, stir at 80 °C in a water bath for 2 to 4 h until it becomes pasty, transfer it to an oven for drying, the temperature is 60 to 80 °C, and the time is 12 to 15 h. After drying, calcine it in a muffle furnace at 600 to 700 °C for 3 to 5 h to obtain the surface-coated Ni 0.5 Cu 0.5 V2O6 / RuO2 material.

[0114] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0115] Example 1

[0116] (1) Disperse 1.46 g of vanadium pentoxide powder in 120 ml of deionized water, and slowly add 18.7 ml of 30% hydrogen peroxide solution drop by drop under the stirring of a magnetic stirrer at a stirring rate of 300 revolutions per minute to obtain a mixed solution.

[0117] (2) Make up the mixed solution obtained in step (1) with deionized water to make the total volume of the solution 150 ml. The molar concentration of vanadium pentoxide powder in the mixed solution is 0.053 mol / L. After magnetic stirring in a 60 °C water bath for 0.5 h at a stirring rate of 300 revolutions per minute, transfer it to a hydrothermal reaction kettle with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 230 °C, and the hydrothermal reaction time is 12 h to obtain a solid-liquid mixture containing yellow flocculent vanadium pentoxide nano-precursor. Centrifuge the solid-liquid of the solid-liquid mixture, wash it 3 times with deionized water, dry it at 80 °C under vacuum for 12 h, and calcine it in a muffle furnace at 400 °C for 3 h. The heating rate of the muffle furnace is 5 °C / mi5 to obtain vanadium pentoxide nano-precursor.

[0118] (3) Dissolve 1.16 g of nickel nitrate hexahydrate, 0.77 g of copper nitrate trihydrate and 2.88 g of complexing agent glucose in 58.2 ml of deionized water. Add the vanadium pentoxide nano-precursor obtained in step (2). Under the stirring of a magnetic stirrer at a stirring rate of 400 revolutions per minute, after fully mixing and dispersing evenly, continue to stir for 3 h under the condition of an 80°C water bath to obtain a wet gel. Transfer it to an oven for drying at a temperature of 60°C for 45 h to obtain a dry gel. First, calcine the obtained dry gel in a muffle furnace at 350°C for 2 h, with a heating rate of the muffle furnace of 5°C / min. After cooling and grinding, then calcine it in the muffle furnace at 600°C for 4 h to obtain Ni 0.5 Cu 0.5 V2O6 composite oxide;

[0119] (4) Dissolve 0.33 g of ruthenium(III) chloride trihydrate in 41.4 ml (mass 41.4 g) of deionized water. Add the Ni 0.5 Cu 0.5 V2O6 composite oxide obtained in step (3). Stir at 80°C in a water bath for 4 h until it becomes paste-like. Under the stirring of a magnetic stirrer at a stirring rate of 400 revolutions per minute, transfer it to an oven for drying at a temperature of 70°C for 14 h. After drying, calcine it in a muffle furnace at 650°C for 4 h, with a heating rate of the muffle furnace of 5°C / min to obtain the surface-coated Ni 0.5 Cu 0.5 V2O6 / RuO2 material, where the coating amount of RuO2 is 8% of the mass of Ni 0.5 Cu 0.5 V2O6.

[0120] Example 2

[0121] (1) Disperse 1.07 g of vanadium pentoxide powder in 120 ml of deionized water. Under the stirring of a magnetic stirrer at a stirring rate of 300 revolutions per minute, slowly add 14.2 ml of 30% hydrogen peroxide solution drop by drop to obtain a mixed solution.

[0122] (2) Make up the mixed solution obtained in step (1) with deionized water to make the total volume of the solution 150 ml. The molar concentration of vanadium pentoxide powder in the mixed solution is 0.04 mol / L. After magnetic stirring in a 60°C water bath for 0.5 h at a stirring rate of 300 revolutions per minute, transfer it to a hydrothermal reaction kettle with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 240°C and the hydrothermal reaction time is 10 h to obtain a solid-liquid mixture containing yellow flocculent vanadium pentoxide nano-precursor. Centrifuge the solid-liquid mixture of the solid-liquid, wash it 3 times with deionized water, dry it under vacuum at 70°C for 14 h, and calcine it in a muffle furnace at 400°C for 3 h, with a heating rate of the muffle furnace of 5°C / min to obtain the vanadium pentoxide nano-precursor.

[0123] (3) 0.87 g of nickel nitrate hexahydrate, 0.73 g of copper nitrate trihydrate and 2.16 g of complexing agent glucose were dissolved in 43.6 ml of deionized water, and the vanadium pentoxide nano-precursor obtained in step (2) was added. The mixture was stirred with a magnetic stirrer at a rate of 400 rpm, and the mixture was fully mixed and dispersed uniformly. The mixture was stirred in a water bath at 80° C. for 2 h to obtain a wet gel. The wet gel was dried in an oven at a temperature of 70° C. for 50 h to obtain a dry gel. The obtained dry gel was first calcined in a muffle furnace at 350° C. for 2 h, with a heating rate of 5° C. / min. After cooling and grinding, the dry gel was calcined in a muffle furnace at 600° C. for 3 h to obtain Ni 0.5 Cu 0.5 V2O6 composite oxide;

[0124] (4) Dissolve 0.15 g of ruthenium trichloride trihydrate in 31.1 ml (mass 31.1 g) of deionized water and add the Ni obtained in step (3). 0.5 Cu 0.5 The V2O6 composite oxide was stirred in a water bath at 80°C for 2 h until it became a paste. Under the stirring of a magnetic stirrer, the stirring rate was 400 rpm, and it was transferred to an oven for drying at 60°C for 15 h. After drying, it was calcined in a muffle furnace at 700°C for 3 h. The heating rate of the muffle furnace was 5°C / mi5 to obtain a surface-coated Ni 0.5 Cu 0.5 V2O6 / RuO2 material, in which the RuO2 coating amount is Ni 0.5 Cu 0.5 5% by mass of V2O6.

[0125] Example 3

[0126] (1) 1.64 g of vanadium pentoxide powder was dispersed in 120 ml of deionized water. Under the stirring of a magnetic stirrer at a rate of 300 rpm, 21.3 ml of 30% hydrogen peroxide solution was slowly added dropwise to obtain a mixed solution.

[0127] (2) Add deionized water to the mixed solution obtained in step (1) to make the total volume of the solution 150 ml, the molar concentration of vanadium pentoxide powder in the mixed solution is 0.06 mol / L, and after magnetic stirring in a 60° C. water bath for 0.5 h, the stirring rate is 300 rpm, and the mixed solution is transferred to a hydrothermal reactor with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 220° C. and the hydrothermal reaction time is 15 h to obtain a solid-liquid mixture containing a yellow flocculent vanadium pentoxide nano precursor. The solid-liquid mixture is centrifuged, washed with deionized water 3 times, vacuum dried at 70° C. for 10 h, and calcined in a muffle furnace at 400° C. for 3 h. The heating rate of the muffle furnace is 5° C. / mi5 to obtain a vanadium pentoxide nano precursor.

[0128] (3) 1.31 g nickel nitrate hexahydrate, 1.07 g copper nitrate trihydrate and 3.24 g glucose as a complexing agent were dissolved in 65.4 ml deionized water, and the vanadium pentoxide nano-precursor obtained in step (2) was added, and the mixture was stirred with a magnetic stirrer at a rate of 400 rpm, and the mixture was thoroughly mixed and dispersed uniformly, and then stirred in an 80° C. water bath for 4 h to obtain a wet gel, which was then dried in an oven at a temperature of 80° C. for 40 h to obtain a dry gel. The obtained dry gel was first calcined in a muffle furnace at 350° C. for 2 h, and the heating rate of the muffle furnace was 5° C. / min. After cooling and grinding, the dry gel was calcined in a muffle furnace at 600° C. for 5 h to obtain Ni 0.5 Cu 0.5 V2O6 composite oxide;

[0129] (4) Dissolve 0.46 g of ruthenium trichloride trihydrate in 46.6 ml (mass 46.6 g) of deionized water and add the Ni obtained in step (3). 0.5 Cu 0.5 The V2O6 composite oxide was stirred in a water bath at 80°C for 3 h until it became a paste. Under the stirring of a magnetic stirrer, the stirring rate was 400 rpm, and it was transferred to an oven for drying at 80°C for 12 h. After drying, it was calcined in a muffle furnace at 600°C for 5 h. The heating rate of the muffle furnace was 5°C / mi5 to obtain a surface-coated Ni0.5Cu 0.5 V2O6 / RuO2 material, in which the RuO2 coating amount is Ni 0.5 Cu 0.5 10% of the mass of V2O6.

[0130] Comparative Example 1

[0131] (1) 1.46 g of vanadium pentoxide powder was dispersed in 120 ml of deionized water. Under the stirring of a magnetic stirrer at a rate of 300 rpm, 18.7 ml of 30% hydrogen peroxide solution was slowly added dropwise to obtain a mixed solution.

[0132] (2) Add deionized water to the mixed solution obtained in step (1) to make the total volume of the solution 150 ml, the molar concentration of vanadium pentoxide powder in the mixed solution is 0.053 mol / L, and after magnetic stirring in a 60° C. water bath for 0.5 h, the stirring rate is 300 rpm, and the mixed solution is transferred to a hydrothermal reactor with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 230° C. and the hydrothermal reaction time is 12 h to obtain a solid-liquid mixture containing a yellow flocculent vanadium pentoxide nano precursor. The solid-liquid mixture is centrifuged, washed with deionized water 3 times, vacuum dried at 80° C. for 12 h, and calcined in a muffle furnace at 400° C. for 3 h. The heating rate of the muffle furnace is 5° C. / mi5 to obtain a vanadium pentoxide nano precursor.

[0133] (3) Dissolve 2.33 g of nickel nitrate hexahydrate and 2.88 g of complexing agent glucose in 58.2 ml of deionized water. Add the vanadium pentoxide nano-precursor obtained in step (2). Under the stirring of a magnetic stirrer at a stirring rate of 400 revolutions per minute, after fully mixing and dispersing evenly, continue to stir for 3 h under the condition of an 80 °C water bath to obtain a wet gel. Transfer it to an oven for drying at a temperature of 60 °C for 45 h to obtain a dry gel. First, calcine the obtained dry gel in a muffle furnace at 350 °C for 2 h, with a heating rate of the muffle furnace of 5 °C / min. After cooling and grinding, then calcine it in the muffle furnace at 600 °C for 4 h to obtain NiV₂O₆ composite oxide.

[0134] Comparative Example 2

[0135] (1) Disperse 1.46 g of vanadium pentoxide powder in 120 ml of deionized water. Under the stirring of a magnetic stirrer at a stirring rate of 300 revolutions per minute, slowly add 18.7 ml of 30% hydrogen peroxide solution drop by drop to obtain a mixed solution.

[0136] (2) Make up the mixed solution obtained in step (1) with deionized water to make the total volume of the solution 150 ml. The molar concentration of vanadium pentoxide powder in the mixed solution is 0.053 mol / L. After magnetic stirring in a 60 °C water bath for 0.5 h at a stirring rate of 300 revolutions per minute, transfer it to a hydrothermal reaction kettle with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 230 °C, and the hydrothermal reaction time is 12 h to obtain a solid-liquid mixture containing yellow flocculent vanadium pentoxide nano-precursor. Centrifuge the solid-liquid mixture, wash it 3 times with deionized water, dry it in vacuum at 80 °C for 12 h, and calcine it in a muffle furnace at 400 °C for 3 h, with a heating rate of the muffle furnace of 5 °C / min to obtain vanadium pentoxide nano-precursor.

[0137] (3) Dissolve 1.73 g of copper nitrate trihydrate and 2.88 g of complexing agent glucose in 58.2 ml of deionized water. Add the vanadium pentoxide nano-precursor obtained in step (2). Under the stirring of a magnetic stirrer at a stirring rate of 400 revolutions per minute, after fully mixing and dispersing evenly, continue to stir for 3 h under the condition of an 80 °C water bath to obtain a wet gel. Transfer it to an oven for drying at a temperature of 60 °C for 45 h to obtain a dry gel. First, calcine the obtained dry gel in a muffle furnace at 350 °C for 2 h, with a heating rate of the muffle furnace of 5 °C / min. After cooling and grinding, then calcine it in the muffle furnace at 600 °C for 4 h to obtain CuV₂O₆ composite oxide.

[0138] Comparative Example 3

[0139] (1) 1.46 g of vanadium pentoxide powder was dispersed in 120 ml of deionized water. Under the stirring of a magnetic stirrer at a rate of 300 rpm, 18.7 ml of 30% hydrogen peroxide solution was slowly added dropwise to obtain a mixed solution.

[0140] (2) Add deionized water to the mixed solution obtained in step (1) to make the total volume of the solution 150 ml, the molar concentration of vanadium pentoxide powder in the mixed solution is 0.053 mol / L, and after magnetic stirring in a 60° C. water bath for 0.5 h, the stirring rate is 300 rpm, and the mixed solution is transferred to a hydrothermal reactor with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 230° C. and the hydrothermal reaction time is 12 h to obtain a solid-liquid mixture containing a yellow flocculent vanadium pentoxide nano precursor. The solid-liquid mixture is centrifuged, washed with deionized water 3 times, vacuum dried at 80° C. for 12 h, and calcined in a muffle furnace at 400° C. for 3 h. The heating rate of the muffle furnace is 5° C. / mi5 to obtain a vanadium pentoxide nano precursor.

[0141] (3) 1.16 g nickel nitrate hexahydrate, 0.77 g copper nitrate trihydrate and 2.88 g glucose as a complexing agent were dissolved in 58.2 ml deionized water, and the vanadium pentoxide nano-precursor obtained in step (2) was added, and the mixture was stirred with a magnetic stirrer at a stirring rate of 400 rpm, and the mixture was fully mixed and dispersed uniformly, and then stirred in an 80° C. water bath for 3 h to obtain a wet gel, which was then dried in an oven at a temperature of 60° C. for 45 h to obtain a dry gel. The obtained dry gel was first calcined in a muffle furnace at 350° C. for 2 h, and the heating rate of the muffle furnace was 5° C. / min5. After cooling and grinding, the dry gel was calcined in a muffle furnace at 600° C. for 4 h to obtain Ni 0.5 Cu 0.5 V2O6 composite oxide.

[0142] Comparative Example 4

[0143] (1) 1.46 g of vanadium pentoxide powder was dispersed in 120 ml of deionized water. Under the stirring of a magnetic stirrer at a rate of 300 rpm, 18.7 ml of 30% hydrogen peroxide solution was slowly added dropwise to obtain a mixed solution.

[0144] (2) Add deionized water to the mixed solution obtained in step (1) to make the total volume of the solution 150 ml. The molar concentration of vanadium pentoxide powder in the mixed solution is 0.053 mol / L. After magnetic stirring in a water bath at 60 °C for 0.5 h with a stirring rate of 300 revolutions per minute, transfer it to a hydrothermal reactor with a volume of 200 ml for hydrothermal reaction. The hydrothermal reaction temperature is 230 °C and the hydrothermal reaction time is 12 h to obtain a solid-liquid mixture containing yellow flocculent vanadium pentoxide nano-precursor. Centrifuge the solid-liquid mixture to separate the solid from the liquid, wash it 3 times with deionized water, dry it in a vacuum at 80 °C for 12 h, and calcine it in a muffle furnace at 400 °C for 3 h with a heating rate of the muffle furnace of 5 °C / min to obtain the vanadium pentoxide nano-precursor.

[0145] (3) Dissolve 1.73 g of copper nitrate trihydrate and 2.88 g of complexing agent glucose in 58.2 ml of deionized water, add the vanadium pentoxide nano-precursor obtained in step (2), and stir it with a magnetic stirrer at a stirring rate of 400 revolutions per minute. After fully mixing and dispersing evenly, continue to stir for 3 h under the condition of a water bath at 80 °C to obtain a wet gel. Transfer it to an oven for drying at a temperature of 60 °C for 45 h to obtain a dry gel. First, calcine the obtained dry gel in a muffle furnace at 350 °C for 2 h with a heating rate of the muffle furnace of 5 °C / min. After cooling and grinding, calcine it in a muffle furnace at 600 °C for 4 h to obtain the CuV2O6 composite oxide;

[0146] (4) Dissolve 0.33 g of ruthenium(III) chloride trihydrate in 41.4 ml (mass 41.4 g) of deionized water, add the NiV2O6 composite oxide obtained in step (3), stir it into a paste at 80 °C in a water bath for 4 h with a magnetic stirrer at a stirring rate of 400 revolutions per minute, transfer it to an oven for drying at a temperature of 70 °C for 14 h, and calcine it in a muffle furnace at 650 °C for 4 h with a heating rate of the muffle furnace of 5 °C / min to obtain the surface-coated CuV2O6 / RuO2 material, where the RuO2 coating amount is 8% of the mass of CuV2O6.

[0147] The Ni 0.5 Cu 0.5 V2O6 / RuO2 materials prepared in the above Examples 1-3 and the NiV2O6, CuV2O6, Ni 0.5 Cu 0.5 V2O6 and CuV2O6 / RuO2 materials prepared in Comparative Examples 1-4 were tested for their electrochemical performance by the following method:

[0148] The Ni 0.5 Cu 0.5The V2O6 / RuO2 material powder (or the material obtained in the comparative example), conductive agent acetylene black, and binder polyvinylidene fluoride were mixed in a mass ratio of 8:1:1, and then ground into a slurry with N-methylpyrrolidone as the solvent. After grinding for 1 hour, the slurry was evenly coated on nickel foam and vacuum dried at 80°C for 12 hours. Using the traditional three-electrode system, the active material coated on nickel foam was used as the working electrode, a platinum sheet as the counter electrode, and Hg / HgO as the reference electrode, and it was immersed in a 2 mol / L KOH electrolyte to test its constant current charge-discharge performance. The voltage range was 0 - 0.5V, and the current density was 1 A / g. The test results of its cycling performance are shown in Table 1 below: There is a problem with the table

[0149] Table 1 Electrochemical Performance Test

[0150]

[0151] As can be seen from Table 1, the specific capacitance of the Ni 0.5 Cu 0.5 V2O6 / RuO2 material prepared in the example of the present invention is high, and the capacity retention rate is good, that is, the cycling performance is good.

[0152] The preparation processes of Comparative Examples 1 - 4 are the same as that of Example 1, except that the binary metal oxides NiV2O6 and CuV2O6 are obtained in Comparative Examples 1 and 2 respectively, and the ternary metal composite oxide material Ni 0.5 Cu 0.5 V2O6 is prepared in Comparative Example 3, and the binary metal oxide CuV2O6 is surface-coated with RuO2 in Comparative Example 4. Compared with Comparative Examples 1 - 4, when the Ni 0.5 Cu 0.5 V2O6 / RuO2 prepared in Example 1 is used as the electrode material, the specific capacitance and the capacity retention rate are both better. Thus, ternary metal composite and surface coating with RuO2 both play important roles in improving the specific capacitance and cycling performance of the electrode material. Without either of them, the specific capacitance and cycling performance of the product will be significantly weakened, indicating that ternary composite and surface coating with RuO2 play a synergistic role in enhancing the specific capacitance and cycling performance of the electrode material.

[0153] Figure 1 For the Ni 0.5 Cu 0.5 V2O6 / RuO2 material prepared in Example 1 of the present invention and the Ni 0.5 Cu 0.5 V2O6 material prepared in Comparative Example 3, the XRD patterns are shown by Figure 1 As can be seen, the ternary metal composite oxide Ni 0.5 Cu 0.5V2O6 contains two phases, CuV2O6 and NiV2O6. After coating with RuO2, characteristic peaks of RuO2 appeared, but the peak intensity was very weak.

[0154] Figure 2 This is the SEM image of the vanadium pentoxide nano-precursor prepared in Example 1 of the present invention. Figure 3 This is the material Ni prepared in Example 1 of the present invention 0.5 Cu 0.5 SEM image of Ni Figure 4 This is the Ni prepared in Comparative Example 3 of the present invention 0.5 Cu 0.5 SEM image of the V2O6 material. It can be seen from these three images that the vanadium pentoxide nano-precursor is in the shape of slender rods, with a diameter of about 20 - 1005m and a length of about 0.5 - 3μm. After forming the ternary composite oxide, the morphology is an irregular polyhedron with a smooth surface and a particle size of about 0.5 - 2μm. After coating with RuO2, many small particles adhere to the smooth surface of the irregular polyhedron, indicating that RuO2 has been successfully coated on the surface of Ni 0.5 Cu 0.5 V2O6 material surface.

[0155] Figure 5 This is the Ni prepared in Example 1 of the present invention 0.5 Cu 0.5 First galvanostatic charge-discharge curve of the Ni Figure 5 Cu

[0156] It can be seen that the voltage range of charge and discharge is 0 - 0.5V, and the initial discharge specific capacitance is 161.4F / g at a current density of 1A / g.

[0157] In summary, for the supercapacitor material of the embodiment of the present invention, the nickel, copper, and vanadium multi-metal composite oxide provides abundant electroactive sites for the Faraday redox reaction. The introduction of multiple metal atoms will lead to an increase in the number of microscopic crystal structure defects. The unbalanced charge distribution can induce a local electric field and provide a Coulomb force to stimulate the diffusion of ions, thereby improving the conductivity of the material; coating ruthenium dioxide on the surface of the nickel, copper, and vanadium composite oxide further increases the electroactive sites on the surface of the electrode material. The presence of ruthenium dioxide can also increase the electron conduction ability on the surface of the material. These synergistic effects among various components will improve the specific capacitance and cycling performance of the electrode material.

[0157] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the patent protection scope of the present invention.

Claims

1. A preparation method of a supercapacitor electrode material, characterized in that, It includes the following steps: S10: Disperse vanadium pentoxide in water, add hydrogen peroxide solution to obtain a mixed solution; S20: Subject the mixed solution to hydrothermal reaction to obtain a solid-liquid mixture, separate the solid and liquid of the solid-liquid mixture, wash, vacuum dry and calcine the obtained solid to obtain a vanadium pentoxide nano-precursor; S30: Dissolve nickel nitrate hexahydrate, copper nitrate trihydrate and a complexing agent in water, add the vanadium pentoxide nano-precursor, heat and stir in a water bath to obtain a wet gel, dry the wet gel and perform secondary calcination to obtain a nickel, copper, vanadium multi-metal composite oxide; S40: Dissolve ruthenium trichloride trihydrate in water, add the nickel, copper, vanadium multi-metal composite oxide, after heating in a water bath, dry and calcine to obtain a supercapacitor electrode material; The supercapacitor electrode material includes a coating layer and a core disposed within the coating layer. The material of the coating layer includes RuO2, and the material of the core includes a nickel, copper, vanadium multi-metal composite oxide. The chemical formula of the nickel, copper, vanadium multi-metal composite oxide is Ni 0.5 Cu 0.5 V2O6; the mass of the coating layer is 5% to 10% of the mass of the core.

2. The preparation method of the supercapacitor electrode material according to claim 1, characterized in that, In step S10, the concentration of vanadium pentoxide in the mixed solution is 0.04 - 0.06 mol / L; and / or, the volume of 30% hydrogen peroxide solution corresponding to each gram of the vanadium pentoxide is 13 mL.

3. The preparation method of the supercapacitor electrode material according to claim 1, wherein, In step S20, the hydrothermal reaction temperature is 220 - 240 °C; and / or, the hydrothermal reaction time is 10 - 15 h; and / or, the vacuum drying temperature is 70 - 90 °C; and / or, the vacuum drying time is 10 - 14 h; and / or, the calcination temperature is 400 °C; and / or the calcination time is 3 h; and / or the heating rate during calcination is 5 °C / min.

4. The preparation method of the supercapacitor electrode material according to claim 1, wherein, In step S20, the vanadium pentoxide nano-precursor is rod-shaped, the cross-sectional diameter of the rod-shaped vanadium pentoxide nano-precursor is 20 - 100 nm; and / or, the length of the rod-shaped vanadium pentoxide nano-precursor is 0.5 - 3 μm.

5. The preparation method of the supercapacitor electrode material according to claim 1, characterized in that, In step S30, the volume of water corresponding to each gram of the nickel nitrate hexahydrate is 50 mL; and / or, the molar ratio of the nickel nitrate hexahydrate, copper nitrate trihydrate, complexing agent and vanadium pentoxide nano-precursor is 0.5:0.5:2:1; and / or, the complexing agent includes glucose; and / or, the water bath temperature is 80 °C; and / or the water bath time is 2 - 4 h; and / or the drying temperature is 60 - 80 °C; and / or, the drying time is 40 - 50 h; and / or, the first calcination temperature is 350 °C; the calcination time is 2 h; and / or the second calcination temperature is 600 °C; the calcination time is 3 - 5 h; and / or the heating rate during calcination is 5 °C / min for both.

6. The preparation method of the supercapacitor electrode material according to claim 1, wherein In step S40, the mass ratio of ruthenium trichloride trihydrate, water and the nickel, copper, vanadium multi-metal composite oxide is (0.098 - 0.196):20:

1.

7. The preparation method of the supercapacitor electrode material according to claim 1, characterized in that, In step S40, the water bath temperature is 80 °C; and / or the water bath time is 2 - 4 h; and / or the drying temperature is 60 - 80 °C; and / or, the drying time is 12 - 15 h.

8. The preparation method of the supercapacitor electrode material according to claim 1, characterized in that, In step S40, the heating rate during calcination is 5 °C / min; and / or, the calcination temperature is 600 - 700 °C; and / or, the calcination time is 3 - 5 h.

Images