Research On Electrochemical Energy Storage Device Based On ZnCo₂O₄ Nano-electrode Material

In order to protect the environment and the gradual consumption of non-renewable energy,the development of clean renewable energy has become a global trend,therefore,the research and development of renewable energy storage equipment has also become a hot spot.The development of supercapacitors has been extremely rapid in recent years because of their ability to charge quickly,superior rate performance,and low internal resistance.At present,supercapacitors have been used in subways,new buses,hybrid vehicles,life electronics,consumer electronics and nano-energy storage electronic devices.Since transition metals have more valences,they have great advantages as electrode materials.With the development and research of capacitors,ZnO,NiO,MnO2,Co2O3 and other transition metal oxide materials with different morphologies on the micro-nano scale are Wide attention.Although binary compounds have certain advantages,with the deepening of scientific research,their power density,energy density and specific capacity can no longer meet people's requirements,so ternary compounds have appeared.Due to higher power density and higher specific capacitance,the synthesis of such a three-dimensional material with a core-shell structure has become the focus of research.In this paper,based on ZnCo2O4 nano-electrode material,the electrochemical properties of its and composite products are studied,and the phase composition,micro-morphology and electrochemical properties of the composite products are tested.The main contents are as follows:First,using foam nickel as a substrate,a simple hydrothermal method was used to prepare a two-dimensional structure of ZnCo2O4 nanowires.The phase structure,valence state change and internal composition of the synthesized product were studied by XRD,XPS and TEM.The microstructure was observed by SEM and the electrochemical performance was tested by electrochemical workstation.When the current density is 10 mA cm^-2,the power density can reach 62.27 W cm^-3.Based on the synthesis of ZnCo₂O₄ nanowire structure,the core-shell structure of ZnCo2O4@CoMoO4 nanoelectrode was prepared by hydrothermal method again,and the electrochemical performance was further improved by compounding two ternary compounds.In the electrochemical test,when the current density is 1mA cm^-2,the area specific capacitance of the ZnCo₂O₄@CoMoO₄ nanoelectrode reaches 3195.6mF cm^-2.Through the secondary hydrothermal synthesis method,firstly,a layer of ZnCo₂O₄nanowires is grown on the nickel foam as a substrate.After that,the surface of the synthesized product was secondary grown with a layer of MnO2 nanosheets to form the ZnCo2O4@MnO2heterostructure.The synthesized ZnCo2O4@MnO2 electrode material was used as the positive electrode to assemble a supercapacitor device.When the voltage window can reach 1.5V and the current density is 2 mA cm^-2,the specific capacity of the ZnCo₂O₄@MnO₂ electrode is 4981mF cm^-2.And in the flexibility test,the capacity retention rate was 90.2%after repeated folding200 times.It shows that it has superior flexibility.