LiMn2O4 prepared by different methods at identical thermal treatment conditions: structural, morphological and electrochemical characteristics

Abstract

Nano-crystalline LiMn2O4 materials were obtained by three different methods: thermal decomposition of mixtures of corresponding metal carbonates or nitrates, Pechini method and self-combustion reaction (SCR) method using common sugar—sucrose as a fuel. Phase composition, morphology, crystallite- and particle sizes of materials were studied by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Contrary to thermal decomposition of metal carbonates or nitrates mixtures, Pechini and SCR methods allowed synthesis of a single-phase product at 400 °C, but the optimal temperature range for preparing of LiMn2O4 spinel with good electrochemical properties was found to be 600–650 °C. Both latter methods provided good control of the chemical composition and microstructure of the active material. The SCR method yields a fine LiMn2O4 spinel, having high initial specific capacity of 116 mA h/g and low capacity fade during cycling. The simple procedure of self-combustion method is time and energy saving, and thus is promising for commercial application.