Particle Morphology and Battery Property of Lithium Manganate Synthesized by Ultrasonic Spray Pyrolysis

摘要

Spherical LiMn_2O_4 fine powders with two different morphologies were prepared by ultrasonic spray pyrolysis. SEM and TEM observation showed tbat the type of starting solution influenced particle morphology. The particle structure derived from nitrate precursor solution was porous, while the powders derived from acetate precursor solution consisted mainly of hollow particles. XRD revealed that as-prepared powders were well crystallized into spinel structure with Fd3^^-m space group. Atomic absorption spectrometer analysis showed that the chemical composition of LiMn_2O_4 was in agreement with that of the starting solution. The first charge/discharge capacity of LiMn_2O_4 obtained from metal nitrate and acetate was 120-130 mAh/g. The discharge capacity of LiMn_2O_4 decreased with increasing cycle number. The cycle performance of LiMn_2O_4 obtained from metal nitrate was superior to that of LiMn_2O_4 obtained from metal acetate. It was found that the cycle perfomance was influenced by the morphology and microstructure of LiMn_2O_4 particles.