Preparation method and application of corn straw-based pseudocapacitor electrode material

Abstract

The invention provides a preparation method and application of a corn straw-based pseudocapacitor electrode material, and the method comprises the steps: firstly weighing corn straw, putting the corn straw into a hydrothermal reaction kettle, adding citric acid for immersion and reaction, washing and drying, then adding the corn straw into an electrolyte for immersion and drying, and under the protection of N2, continuously heating and roasting according to a certain heating rate. Washing the obtained sample with HCl and deionized water respectively, and drying for later use; weighing urea, an activating agent and deionized water, adding the weighed urea, activating agent and deionized water into a hydrothermal reaction kettle, putting the corn straw skeleton into the mixed solution, reacting, washing and drying, calcining the obtained product under the protection of N2 to obtain a carbon-based composite material, and measuring the electrochemical performance of the carbon-based composite material under a three-electrode system. A hollow porous corn stalk carbon skeleton is prepared through temperature programming carbonization and etching pore forming under N2 protection, transition bimetal oxide grows in situ on the surface of the carbon skeleton by adopting a hydrothermal method, and the transition bimetal oxide is applied to an electrochemical electrode material.

Description

Technical field: [0001] The invention relates to the technical field of supercapacitors, in particular to a preparation method and application of a corn stalk-based transition double metal oxide pseudocapacitive electrode material. Background technique: [0002] With the continuous increase of energy consumption and the continuous improvement of environmental protection requirements, the development of energy storage materials is facing great challenges. Among various energy storage devices, supercapacitors (SCs) are a new type of energy storage device between traditional capacitors and batteries. This device has the characteristics of high-energy pulse, fast charging and discharging process, and stability and safety. The performance of SCs largely depends on the electrode materials. Currently, various materials (such as carbon materials, transition metal oxides, conducting polymers) have been extensively studied as electrode materials. Among them, the transition metal oxi...

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Problems solved by technology

However, when single metal oxides are used as electrode materials, the structure changes after hundreds of cycles, so they exhibit the disadvantages of low electrical conductivity and poor cycle performance.

[0003] Transitional double metal oxides have attracted much attention because they contain two metal ions and can provide more abundant redox reactions (L.Q.Mai, F.Yang, Y.L.Zhao, X.Xu, L.Xu, Y.Z.Luo, Nat .commun.,2,381(2011); L.Y.Lin,H.Y.Lin,W.L.Hong,Thin solid films.667,69-75(2018);W.Qiu,H.Xiao,M.Yu,Chem.Eng.J.352,996 -1003(2018); D.Khalafallah, O.Y.Alothman, H.Fouad, J.Electrochem.Soc.165, F1067-F1074(2018)), however, it still has two shortcomings as an electrode material: on the one hand, its conductivity Although the rate of oxidation has been enhanced relative to the oxide, it still needs to be further improved in order to solve the defect of its poor kinetic performance in the redox reaction; on the other hand, the Faraday redox reaction only occurs on the surface of the electrode material, and the electrolyte enters the electrode The diffusion distance is short, making it difficult to participate in the electrochemical charge storage process inside

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