Preparation And Electrochemical Capacitance Performance Study Of Cobalt-based Compound Nanostructure Arrays

In recent years, nanomaterials have become the research focus due to theirexceptional properties and applications. Nanostructure arrays of cobalt based compoundsare widely used as electrode materials for high-performance devices such assupercapacitors, solar batteries, lithium-ion batteries and others owing to their uniquestructural and capacitor performance. In this paper, we use Co3O4nanowires for sacrificetemplate hydrothermal to prepare Co3S4nanosheet arrays. On this basis, we directly useCo3O4nanowires and Co3S4nanosheet arrays as electrode for the capacitanceperformance test. We synthesize ZnCo2O4nanowires growing on Ni foam byhydrothermal method. The ZnCo2O4nanowires are directly used as electrodes forcapacitor performance test. On the same time ZnCo2O4nanowires will be assembled intosupercapacitor. We have obtained some important results. The main contents are asfollows:1. Using the method of hydrothermal growth to Co3O4nanowires array on nickelfoam. Experiments show that high purity Co3O4nanowires of our preparation array haveabout80nm in diameter and adjacent Co3O4nanowires slightly bend and clump at the topof the nanowires forming leaf-like structures. This kind of structure is conducive toformation of the Co3S4nanosheet arrays.2. With the hydrothermal preparation of Co3O4nanowires array as a template, weprepare porous single crystal line Co3S4nanosheet arrays. Electrochemical tests show thatthe Co3S4nanosheet arrays have good electrical conductivity, and thus high performanceas electrode when directly testing the capacitance. When the current density is4mA·cm-2,area capacitance is2.69F·cm-2. After charging and discharging3000times cycle in a row,capacitance remains96.2%at a fairly high current density of24mA·cm-2. Our resultsshow that Co3S4nanosheet array is expected to have important applications in the futureas supercapacitor electrode materials.3. ZnCo2O4nanowire arrays are synthesized by hydrothermal method in nickel foam.Experiments show that high purity ZnCo2O4nanowires of our preparation array haveabout4um in length. Electrochemical tests show that the ZnCo2O4nanosheet arrays havegood electrical conductivity. When the current density is10mA·cm-2, area capacitance is1.52F·cm-2. After charging and discharging2000times cycle in a row, capacitanceremains86.2%at current density of10mA·cm-2. Further we directly assemble ZnCo2O4nanowires electrode into the supercapacitor. After charging supercapacitor, we make it connect to a red LED lamp, which can provide dozens of seconds of the red LED normallight. The experimental results show that ZnCo2O4nanowire arrays have potentialapplication in the aspect of supercapacitor electrode materials.