Method for preparing carbon-coated Ni3S2/graphene composite material for supercapacitor electrode

Abstract

The invention relates to a method for preparing a carbon-coated Ni3S2/graphene composite material for a supercapacitor electrode and belongs to the field of preparation of nanometer composite materials. The method comprises the steps that graphite oxide, glucose, a certain amount of nickel chloride and thiourea are dissolved in a mixed solution of water and ethyl alcohol through ultrasound, ammonium hydroxide is added to the mixed solution under the condition of stirring, the mixed solution reacts for six to twelve hours in a reaction still at the temperature of 180 DEG C, sediment is collected, and then the carbon-coated Ni3S2/graphene composite material is obtained. According to the carbon-coated Ni3S2/graphene composite material, Ni3S2 nanometer particles are all coated with carbon shells, the carbon-coated Ni3S2 particles are all attached to a graphene sheet, and a high-uniformity structure is obtained; due to carbon coating, the Ni3S2 particles can be protected against oxidation, and the conductivity and the specific surface area of the material can be improved through graphene; the composite material has excellent capacitive performance, and hopefully the composite material is used as a supercapacitor electrode material.

Description

technical field [0001] The invention belongs to the field of preparation of nanocomposite materials, in particular to a carbon-coated Ni 3 S 2 / The preparation method of graphene composite supercapacitor electrode material. Background technique [0002] Since 2004, when A. K. Geim, professor of physics at the University of Manchester, used adhesive tape to peel off graphite crystals to prepare graphene for the first time, graphene has rapidly become the most active research hotspot in the fields of chemistry, materials science and condensed matter physics; compared with other carbon materials , the graphene material has a higher specific surface area (2630 m 2 / g) and outstanding electrical conductivity, making graphene the most ideal nanomaterial carrier, combining functional materials with graphene can greatly improve their performance, making graphene-based composite materials widely used in many fields . [0003] Supercapacitor is a new type of energy storage device....

AI Technical Summary

Problems solved by technology

[0003] Supercapacitor is a new type of energy storage device. Due to its short charging time, long service life, good temperature characteristics, energy saving and environmental protection, its appearance has immediately attracted great attention in the field of energy and materials; the traditional supercapacitor Capacitor electrode materials mainly include metal oxides and polymers. However, due to the disadvantages of small specific capacitance and poor cycle performance, the application of these two electrode materials is limited; in recent years, metal sulfides have been used due to their high However, like other electrode materials, metal sulfides are restricted by poor electrical conductivity and small specific surface area, and cannot give full play to the inherent capacitance characteristics of this type of material; combining metal sulfides with graphene Composite composite materials are expected to bring into play the respective advantages of metal sulfides and graphene, as well as the synergistic effect between the two, thereby significantly improving the capacitance performance of the material; the present invention uses glucose as a carbon-coated carbon source. On-chip in-situ preparation of carbon-coated nickel disulfide nanocomposites. The presence of graphene not only increases the conductivity of the composite, but also increases the contact area between the electrode material and the solution. At the same time, the carbon coating improves the chemical properties of the electrode active material. Stability, which is beneficial to improve the cycle stability of electrode materials

[0004] Recently, Pan et al. published a synthetic Ni 3 S 2 The method of / graphene uses organometallics as the nickel source, but the specific capacitance of the prepared composite is less, and the stability is poor; in the present invention, we use the more common nickel chloride as the nickel source, adopting simple One-step hydrothermal synthesis to prepare carbon-coated Ni 3 S 2 / graphene composite material, the composite has more excellent specific capacitance and higher electrochemical stability when used as an electrode material

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