Preparation of high-entropy ceramic oxide powder at different calcination temperatures and electrochemical applications

Abstract

High entropy ceramic oxide (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O (HEO) powders were synthesized by precipitation. X-ray diffraction (XRD), thermogravimetric analysis (TG-DSC), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were used to characterize the morphologies and structures of powders obtained at different calcination temperatures. The results showed that with increasing calcination temperature, the powder changed from a flocky precursor to a compact block shape. Due to the influence of the diffusion rates of different elements, the powder morphologies and structures differed for different calcination temperatures. Finally, the electrochemical properties of HEO powders prepared by the precipitation method were tested. The results showed that HEOs exhibited good electrochemical performance. The initial cyclic discharge capacity was 624.3 F/g; after cycling with different current densities, the discharge capacity still reached 591.3 F/g when cycled at 0.1 A/g, which was attributed to the good cycling performance and rate performance.