Study On The Preparation And Electrochemical Properties Of Cobalt Based Supercapacitor Eledctrode Materials

As a new generation of green energy storage equipment,supercapacitor which exhibited high power density,fast charge and discharge speed,long cycle life and other advantages,has great research value.With respect to the core of supercapacitors,the electrode materials can be divided into three groups:?i?carbon materials?ii?conducting polymers and?iii?metal oxides.Apart from high specific surface area,the design of nanoarchitectures for supercapacitor electrodes is an effective way to improve electrochemical performance.This is because the nanoarchitecture gives a broader real reaction area and enhances the efficient charge and mass exchange.In this paper,cobalt-based composites were mainly used to study the following three composite materials:cobalt tetroxide/nickel-aluminum hydrotalcite,nickel-cobaltate/polypyrrole,nickel-cobaltate/polypyrrole/manganese dioxide,and the electrochemical performance of the pseudocapacitance electrode material has been optimized.The details are as follows:Cobalt tetroxide?Co3O4/Ni-Al LDHs?with nanowire structure was deposited on the foamed nickel substrate using a simple hydrothermal method.The cobalt-alumina hydrotalcite was coated on the surface of the ceric oxide nanowires by chemical bath deposition.Nanosheets,the product exhibits a typical hierarchical core-shell nanowire structure,this hierarchical structure has a good synergistic effect,cobalt oxide nanowires as a core material,provides a stable electronic channel for electrochemical reactions,nickel coated on nanowires aluminum hydrotalcite nanosheets can effectively increase the specific surface area of the electrode material.This synergistic effect can greatly improve the electrochemical performance of the electrode material.NiCo2O4/PPy composites were prepared on a flexible carbon cloth by a simple hydrothermal method and chemical polymerization method.Coating with highly conductive PPy can significantly improve the charge transfer process and improve electrochemical performance.The electrochemical properties of the composites were modified by adjusting the amount of pyrrole and ammonium persulfate?APS?.The results showed that the composite has the good performance when the dosage of pyrrole and APS were 0.1 mL and0.12 g,respectively.The capacitance reached 1.05 F/cm² when the current density was 1mA/cm².NiCo₂O₄/PPy/MnO₂ composites were prepared by three-step method,which was directly grown on carbon cloth.The synergistic effect of this heterogeneous structure nanocomposites material leads to a reduction in the overall charge transfer internal resistance.And the flaky structure of MnO2 can increase the specific surface area of the material and facilitate the penetration of the electrolyte.The electrochemical properties of the composites were investigated by different soaking numbers.The results showed that when the number of soaking times is 2,the sample has the best performance.The capacitance is 1.21 F/cm² when the current density is 1 mA/cm².