Method for improving performance of Co(OH)2 supercapacitor through double-potential interval activation

Abstract

The invention discloses a method for improving the performance of a Co(OH)2 supercapacitor through double-potential-interval activation, and the method comprises the steps: taking foamed nickel as a substrate, taking cobalt nitrate as a nickel source, taking urea as a nucleating agent, and obtaining a Co(OH)2 precursor nanowire array through a hydrothermal method; and performing cyclic voltammetry treatment on the precursor in different potential intervals to obtain the activated Co(OH)2 electrode. A cyclic voltammetry method is adopted, after a Co(OH)2 precursor is activated in a positive potential interval, a large number of nanosheets are formed on the surface of the nanowire, more electrochemical active sites are achieved, electrolyte infiltration and electrolyte ion transmission are facilitated, charging and discharging are conducted under the current density of 10 mA cm<-2>, and the specific capacitance is increased to 1.78 F cm<-2>; and after activation in the negative potential interval, part of Co2+ is reduced into Co elementary substances, the internal resistance of the sample is reduced to 1.28 ohm, and the specific capacitance is increased to 2.12 F cm<-2>, which is 1.2 times of that of the sample only activated in the positive potential interval and 3.8 times of that of the sample not activated.

Description

technical field [0001] The supercapacitor field of the present invention is specifically related to a method for improving Co(OH) 2 method for supercapacitor capacity. Background technique [0002] Co(OH) 2 As a typical pseudocapacitor electrode material, it has the advantages of high theoretical capacity, simple preparation method, and easy control of morphology, and has attracted much attention in supercapacitor electrode materials. However, limited by the microstructure and conductivity, Co(OH) 2 The actual capacity is generally much lower than its theoretical capacity. A large number of studies have shown that adjusting the microstructure of materials to increase active sites and improve the conductivity of materials is an effective way to obtain high-capacity electrode materials. At present, the control of the microstructure of electrode materials is mainly achieved by preparing various nanostructures, such as nanosheets, nanorods, nanowires, and nanoflowers. Altho...

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Problems solved by technology

Among them, carbon coating usually requires a higher temperature, which is not suitable for some materials that cannot be treated at high temperature (such as hydroxide), and usually only modifies the outer surface of the material; while phosphating and vulcanization require different phosphorus Phosphating and vulcanizing agents are used to process samples, which not only adds additional process steps and takes a long time, but also produces a large number of by-products during the phosphating and vulcanization processes, which corrode equipment and even produce toxic by-products

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