The Synthesis of ZnMn<inf>2</inf>O<inf>4</inf> by Glycine Nitrate Combustion and an Examination of Its Electrochemical Properties in Aqueous Solutions of ZnCl<inf>2</inf> and NaNO<inf>3</inf>

Abstract

Abstract: To research potential replacements for LiMn2O4, this work carries out a synthesis of ZnMn2O4 (ZMO) through the glycine-nitrate combustion. XRPD validates its phase characterization; electron micro-scopy confirmed the presence of single phase ZMO in the form of curvy and rod-shaped sub-micron sized particles at an average of 113 nm. This work is novel for its electrochemical measurements of ZMO as a cathodic material for alkali-ion batteries, performed by cyclic voltammetry in aqueous solutions of ZnCl2 and NaNO3 ranging from 5 to 100 mV s–1 polarization rates, yielding stable capacities for both electrolytes. The highest capacities were obtained for the polarization speed of 5 mV s–1 for both electrolytes. Their cathode capacities were 11.3 and 27.2 mA h g–1 for ZnCl2 and NaNO3, respectively. Concerning Na-ions batteries, the surface storage is the deciding factor due to the adsorption of Na+ ions on the λ-MnO2 phase. Unlike Zn-ions, Na+ ions cannot intercalate into the spinel structured materials.