Composite electrode material and supercapacitor

Abstract

The present invention relates to the field of supercapacitor electrode materials, specifically to a composite electrode material and a supercapacitor, comprising a carbon material and a ternary metal oxide; at least one of the metal elements in the ternary metal oxide is a transition metal element, and the carbon material and the ternary metal oxide are composited to form an electrode material having a high specific capacitance value, a high capacitance retention rate, and good cycle stability.

Description

Technical Field

[0001] The present invention relates to the field of supercapacitor electrode materials, and in particular to a composite electrode material and a supercapacitor. Background Art

[0002] Supercapacitors have attracted widespread attention due to their high specific capacitance, high power density, and long life. They are a new type of energy storage device that is between batteries and ordinary capacitors, combining the characteristics of both, and can assist or replace batteries. The operating principle of supercapacitors is different from the charge transfer dynamics of traditional batteries. No chemical reaction occurs during the charging and discharging process. The storage or release of electrical energy is completed through a physical process established by an electrostatic field. The electrodes and electrolytes hardly age, have a long service life, can be charged and discharged rapidly, and have a charge storage capacity 3-4 orders of magnitude higher than that of ordinary capacitors. Therefore, supercapacitors have great application value in portable electronic devices, electric vehicles, aerospace, electronic communications and other fields.

[0003] Metal oxides can store and release energy by transferring electrons through fast and reversible redox reactions, but their low electrical conductivity and poor cycle life also restrict their practical application as supercapacitor electrode materials. Summary of the Invention

[0004] Purpose of the invention: In response to the above technical problems, the present invention proposes a composite electrode material and a supercapacitor.

[0005] The technical solutions adopted are as follows:

[0006] A composite electrode material comprising a carbon material and a ternary metal oxide;

[0007] At least one of the metal elements in the ternary metal oxide is a transition metal element.

[0008] Furthermore, the weight ratio of the carbon material to the ternary metal oxide is 1-10:1-10.

[0009] Furthermore, the metal elements in the ternary metal oxide are Ni, Fe, and Al.

[0010] Furthermore, the ternary metal oxide has a petal-like structure.

[0011] Furthermore, the preparation method of the ternary metal oxide is as follows:

[0012] Dissolve soluble iron salt, soluble aluminum salt and soluble nickel salt in water to obtain a mixed salt solution. Add a precipitant to the mixed salt solution, seal it and heat it to 140-160℃ to react for more than 5h. After the reaction is completed, return it to room temperature, collect the precipitate, wash it, dry it and roast it.

[0013] Furthermore, the calcination temperature is 850-950° C., and the calcination time is 2-4 hours.

[0014] Furthermore, the carbon material is sulfonated graphene.

[0015] Furthermore, the preparation method of the sulfonated graphene is as follows:

[0016] Dissolve p-aminobenzenesulfonic acid in a sodium hydroxide solution, cool the resulting solution to below 0°C, add sodium nitrite, add a hydrochloric acid solution dropwise, collect the precipitate and dry it to obtain a diazonium salt, reduce the graphite oxide with a reducing agent once to obtain reduced graphite oxide, prepare a suspension, cool the suspension to below 0°C, add the diazonium salt, stir the reaction for more than 5 hours, and then reduce it with a reducing agent for a second time to obtain the sulfonated graphene.

[0017] Furthermore, the reducing agent is any one or more combinations of sodium borohydride, ascorbic acid, hydrazine hydrate, sodium thiosulfate, and sodium citrate.

[0018] The present invention also provides a supercapacitor comprising the composite electrode material.

[0019] Beneficial effects of the present invention:

[0020] The present invention provides a composite electrode material. Multinary metal oxides have large specific capacitance but poor electrical conductivity, while carbon materials have excellent electrical conductivity but low specific capacitance. Composite carbon materials and multinary metal oxides can combine the advantages of both, improving defects of carbon materials or multinary metal oxides when used as electrode materials. Al ions in the ternary metal oxides with a special petal-shaped structure maintain the stability of the system, while Ni and Fe ions provide higher electrical conductivity and capacitance response during the cycle. Graphene conductivity is improved after sulfonation, avoiding the accumulation of flakes. After composite with the ternary metal oxide, the electrode material has a high specific capacitance value and a high capacitance retention rate, showing good cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the SEM image of NiFeAlO4 prepared in Example 1. DETAILED DESCRIPTION

[0022] Unless otherwise specified, the following examples and comparative examples were conducted in parallel, using the same processing steps and parameters.

[0023] Example 1:

[0024] A composite electrode material comprises sulfonated graphene and NiFeAlO4 in a weight ratio of 1:1, wherein the two are mixed and ball-milled for 5 hours using ethanol as a ball-milling medium and then dried.

[0025] Wherein, the preparation method of NiFeAlO4 is as follows:

[0026] Dissolve 8.08 g of ferric nitrate nonahydrate, 7.51 g of aluminum nitrate nonahydrate, and 5.82 g of nickel nitrate hexahydrate in 54 ml of water to obtain a mixed salt solution. Add ammonia water to the mixed salt solution to maintain the pH of the solution at 10. Seal the solution and heat it to 150°C for 6 hours. After the reaction, return to room temperature and collect the precipitate. Wash it thoroughly with deionized water and then dry it. Place it in a muffle furnace and heat it to 950°C for calcination for 3 hours to obtain NiFeAlO4 with a petal-like structure.

[0027] The preparation method of sulfonated graphene is as follows:

[0028] Dissolve 2.7g of p-aminobenzenesulfonic acid in 35ml 2% sodium hydroxide solution, the resulting solution was cooled to -5 ° C with a cold trap, 1.2 g of sodium nitrite was added, and the mixture was thoroughly mixed. 4.5 ml of concentrated hydrochloric acid was diluted 5 times with ice water and then added dropwise to the solution. The precipitate was collected and freeze-dried at low temperature to obtain a diazonium salt. 1 g of graphite oxide was dispersed in a beaker filled with 1000 mL of deionized water and ultrasonically oscillated at room temperature for 2 h to obtain a yellow-brown suspension. The suspension was bathed in an 80 ° C water bath and 1 g of sodium borohydride was added for reduction for 2 h. The graphite oxide was gradually reduced to form a black precipitate. The black precipitate was collected, washed thoroughly with deionized water, and dried. It was then prepared into a 1 mg / ml suspension. The suspension was cooled to -5 ° C with a cold trap, and the diazonium salt prepared above was added. The reaction was stirred for 10 h. The precipitate was collected and washed thoroughly with deionized water and dried. Then 1 g of the precipitate was prepared into a 1 mg / ml suspension. The suspension was bathed in an 80 ° C water bath and 1 g of hydrazine hydrate was added for reduction for 2 h. The precipitate was collected and washed thoroughly with deionized water and dried.

[0029] Example 2:

[0030] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 1:2.

[0031] Example 3:

[0032] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 1:4.

[0033] Example 4:

[0034] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 1:6.

[0035] Example 5:

[0036] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 1:8.

[0037] Example 6:

[0038] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 1:10.

[0039] Example 7:

[0040] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 2:1.

[0041] Example 8:

[0042] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 4:1.

[0043] Example 9:

[0044] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 6:1.

[0045] Example 10:

[0046] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 8:1.

[0047] Example 11:

[0048] It is basically the same as Example 1, except that the composite electrode material in this embodiment includes sulfonated graphene and NiFeAlO4 in a weight ratio of 10:1.

[0049] Comparative Example 1:

[0050] It is basically the same as Example 1, except that it does not contain NiFeAlO4.

[0051] Comparative Example 2:

[0052] The method is basically the same as Example 1, except that commercially available graphene (Nanjing Jicang Nanotechnology) is used instead of the homemade sulfonated graphene.

[0053] Performance testing:

[0054] The electrochemical performance of the composite electrode materials in Examples 1-11 of the present invention and Comparative Examples 1-2 was tested using a three-electrode system, wherein the working electrode was a composite electrode material, acetylene black, and polytetrafluoroethylene in a mass ratio of 8:1:1, ground and mixed with ethanol as a medium, and coated on a 1 cm × 1 cm nickel foam, dried and compacted, and a saturated calomel electrode was used as a reference electrode, a platinum sheet was used as a counter electrode, and 1 mol / L H2SO4 was used as an electrolyte to form a three-electrode system. The specific capacitance of the three-electrode system at a current density of 1 A / g and the capacitance retention after 10,000 cycles were tested using a CHI760D electrochemical workstation. The test is shown in Table 1:

[0055] Table 1:

[0056]

[0057] As can be seen from Table 1 above, the composite electrode material provided by the present invention has a relatively high specific capacitance value and a relatively high capacitance retention rate, and exhibits good cycle stability.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A composite electrode material, characterized in that: including carbon materials and ternary metal oxides; The weight ratio of the carbon material to the ternary metal oxide is 1-10:1-10; The metal elements in the ternary metal oxide are Ni, Fe, and Al; The ternary metal oxide has a petal-like structure; The preparation method of the ternary metal oxide is as follows: Dissolve soluble iron salt, soluble aluminum salt, and soluble nickel salt in water to obtain a mixed salt solution. Add a precipitant to the mixed salt solution, seal it, heat it to 140-160°C, and react for more than 5 hours. After the reaction is completed, return it to room temperature, collect the precipitate, wash it, dry it, and then roast it. The calcination temperature is 850-950℃ and the calcination time is 2-4h; The carbon material is sulfonated graphene.

2. The composite electrode material according to claim 1, wherein The preparation method of the sulfonated graphene is as follows: Dissolve p-aminobenzenesulfonic acid in a sodium hydroxide solution, cool the resulting solution to below 0°C, add sodium nitrite, add a hydrochloric acid solution dropwise, collect the precipitate and dry it to obtain a diazonium salt, reduce the graphite oxide with a reducing agent once to obtain reduced graphite oxide, prepare a suspension, cool the suspension to below 0°C, add the diazonium salt, stir the reaction for more than 5 hours, and then reduce it with a reducing agent for a second time to obtain the sulfonated graphene.

3. The composite electrode material according to claim 2, wherein The reducing agent is any one or more combinations of sodium borohydride, ascorbic acid, hydrazine hydrate, sodium thiosulfate, and sodium citrate.

4. A supercapacitor, characterized in that: The composite electrode material comprises the composite electrode material according to any one of claims 1 to 3.

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