Preparation and characterization of spinel LiNi0.5xMg xMn1.5O4 cathode materials via spray pyrolysis method
Mg-substituted LiNi0.4-xMgxMn1.5O4 (x=0, 0.02, 0.05 and 0.10) are prepared via a spray pyrolysis mehtod followed by a two-step heating at 600 degrees celcius for 6 h and 800 degrees celcius for 8 hours in air. The compositions morphology, and crystalline structure are studied with ICP-OES, SEM, XRD, and NPD, respectively. The XRD and NPD results are refined with Rietveld mehtod to reveal the crystallography and phase compostion of the prepared samples. The electrochemical properties of the obtained samples are investigated with results of capacity retention and cyclic voltammetric studies. Samples synthesized in this study manifest promising rate capability that may be due to the presence of major Fd3M phase with a minor amount of P4332. Among the prepared samples, LiNi0.4Mg0.1Mn1.504 demonstrates the lowest capacity fading rate among the prepared samples at 0.1~5C rates when cycled between .5 and 5.1 V at temperatures of 30 and 60 degrees celcius.