Ponente
Descripción
Abstract
Nickel hydroxide is receiving increasing attention, especially due to its electrochemical properties and potential applications in Ni-based rechargeable alkaline batteries, e.g. Ni/Cd, Ni/Zn and Ni/MH. In this work, a facile chemical co-precipitation method to prepare nickel-cobalt layered double hydroxide (Ni/Co-LDH) by industrial solutions is reported. Experimental XRD, FT-IR and Raman results showed that the sample of Ni/Co-LDH (NixCo1-x(OH)2-LDHs) were prepared by this method correspond to the -phase. SEM images showed aggregates of nanoparticles with an architecture formed by uniform nanoflat with lengths between 30 and 50 nm. Other techniques such as TG and N2-adsorption were used to evaluate the thermal stability and surface area of the aggregates. Cyclic voltammetry was used to determine the electrochemical properties of Ni/Co(OH)2 electrode materials in 6 M KOH. The influence of cobalt content on the electrochemical properties of lamellar hydroxides obtained from industrial solutions was evaluated. It was found that the ratio between Ni and Co had a significant effect on their electrochemical activities. The specific capacity of 275.1 mAh/g was achieved when the atomic ratio Ni/Co was equal to 0.69:0.31. This Ni0.69Co0.31(OH)2-LDH sample had a BET specific surface area of 66.75 m2/g and total pore volume of 0.285 cm3/g, and its pore size was mainly in the range of 17 nm, which led to the high liquid-solid interfacial area and further increased the utilization of the active materials. Additionally, the Ni0.69Co0.31(OH)2-LDH electrode exhibited a good electrical conductivity 5.72*10-7 S/cm.
