Graphene-loaded hollow manganese dioxide composite material and preparation method thereof

Abstract

The invention relates to a graphene-loaded hollow manganese dioxide composite material and a preparation method thereof. The preparation method comprises the following steps: adding graphite oxide into water, and performing ultrasonic dispersion to obtain graphene oxide colloid; respectively mixing a manganese salt, L-lysine and sodium borohydride with water to obtain a manganese salt solution, anL-lysine solution and a sodium borohydride solution; mixing the graphene oxide colloid with the manganese salt solution, the L-lysine solution and the sodium borohydride solution in sequence, puttingthe obtained mixture into a hydrothermal kettle, reacting, and dispersing the oxide composite material generated by the reaction in water to obtain a turbid liquid, mixing the turbid liquid with a potassium permanganate solution, washing to obtain a graphene-loaded manganese dioxide composite material, re-dispersing the graphene-loaded manganese dioxide composite material, mixing the re-dispersedgraphene-loaded manganese dioxide composite material with hydrochloric acid, filtering, and washing to obtain the graphene-loaded hollow manganese dioxide composite material. The preparation method is simple in process, and the prepared graphene-loaded hollow manganese dioxide composite material is high in specific capacitance, long in cycle life and excellent in conductivity.

Description

technical field [0001] The invention belongs to the technical field of graphene composite materials. Specifically relates to a graphene-loaded hollow manganese dioxide composite material and a preparation method thereof. Background technique [0002] Graphene is a single layer of graphite. Ideally, graphene is composed of a large number of sp 2 A monoatomic layer of two-dimensional planes composed of hybridized carbon atoms. Graphene has the characteristics of good flexibility, good electrical conductivity and high specific surface area. However, during the preparation process, due to the stacking of graphene sheets, the specific surface area is greatly reduced, so that the specific capacitance is much lower than the theoretical value. However, transition metal oxides as electrode materials have high specific capacitance and energy density when using pseudocapacitance for energy storage. In practical applications, graphene is often combined with transition metal oxides su...

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Problems solved by technology

Therefore, repeated expansion and contraction will occur inside the electrode material, which will cause the electrode material to break and the cycle performance is poor.