Manganese dioxide composite nitrogen-sulfur double-doped porous carbon as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of manganese dioxide composite nitrogen-sulfur double-doped porous carbon. The preparation method comprises the following steps of dissolving thiourea in a dilute acid solution firstly to prepare an acidified thiourea solution, dropwise adding the acidified thiourea solution into a mixed solution in which sodium alginate, potassium nitrate and potassium permanganate are dissolved, and cross-linking to obtain blocky gel; after washing and freeze-drying, carrying out one-step carbonization operation at a certain temperature and under the protection of nitrogen to obtain the manganese dioxide composite nitrogen-sulfur double-doped porous carbon. According to the method, the acidified thiourea and the sodium alginate molecular chains are cross-linked to obtain the gel, wherein the thiourea can serve as a nitrogen source and a sulfur source at the same time, and the potassium permanganate serves as a manganese source, and therefore the manganese dioxide composite nitrogen-sulfur double-doped porous carbon can be prepared through one-step carbonization. By changing the concentration of potassium permanganate, the pore structure of the porous carbon and the content of manganese dioxide can be regulated and controlled, and a supercapacitor taking the obtained porous carbon composite material as an electrode material shows good electrochemical performance.

Description

technical field [0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a manganese dioxide composite nitrogen-sulfur double-doped porous carbon and its preparation method and application. Background technique [0002] Supercapacitors are new energy storage devices between traditional capacitors and chemical batteries. It follows the same basic principles as traditional capacitors, and has the characteristics of fast charging and discharging speed, high efficiency, long cycle life, high power density, safety and environmental protection, and wide operating temperature range of traditional capacitors. At the same time, its electrode has a larger effective specific surface area and a thinner dielectric, making its specific capacitance much higher than that of traditional capacitors, which greatly improves the energy density. Its excellent characteristics make it have very broad application prospects in the electronics ...

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Problems solved by technology

[0003] Although supercapacitors have better power density than fuel cells and lithium-ion batteries, their energy density is far lower than that of batteries, which limits its practical application.

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