Particle morphology and battery properties of lithium manganate synthesized by ultrasonic spray pyrolysis

Spherical LiMn2O4 fine powders with two different morphologies were prepared by ultrasonic spray pyrolysis. Scanning and transmission electron microscope observations showed that the type of starting solution influenced the particle morphology. The particle structure derived from nitrate precursor solution was porous, while the powders derived from acetate precursor solution involved a lot of hollow particles. X-ray diffraction revealed that as-prepared powders were well crystallized to a spinel structure with a Fd3m space group. Atomic absorption spectrometery analysis showed that the chemical composition of LiMn2O4 was in agreement with that of the starting solution. The first charge/discharge capacity of LiMn2O4 obtained from metal nitrate and acetate was 120-130 mAh/g, respectively. The discharge capacity of LiMn2O4 decreased with increasing cycle number. The cycle performance of LiMn2O4 obtained from metal nitrate was superior to that of LiMn2O4 obtained from metal acetate. It was found that the cycle performance was influenced by the morphology and microstructure of LiMn2O4 particles.