Particle properties of LiMn₂O₄ fabricated by ultrasonic spray pyrolysis method

Spinel lithium manganese oxide powders were prepared directly by a continuous droplet-to-particle conversion process using an ultrasonic spray pyrolysis method. Nine kinds of precursor solutions were used to synthesize LiMn₂O₄ powders. The aqueous precursor solutions were made from various combinations of Li-salt, such as Li(HCOO) · H₂O, Li(CH₃COO) · 2 H₂0, Li(NO₃), were Mn(HCOO)₂·2 H₂0, Mn (CH₃COO)₂·4 H₂O or Mn(NO₃) · 6 H₂O. The total concentration of metal ion is 0.54 mol/dm³. The particle properties of as-prepared LiMn₂0₄ powders were examined by X-ray diffraction (XRD), the Brunauer-Emmet-Teller (BET) method, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM). The chemical composition of the powders was determined by inductively coupled plasma spectroscopy (ICP). As the results, the powders were identified as single-phase spinel LiMn₂O₄, and the observed chemical compositions showed, good agreement with the stoichiometry one of LiMn₂O₄ for all samples. However, the particle morphology could be classified into four patterns depending on the original salts. The as-prepared particles were then used as cathode active materials for lithium-ion batteies and their charge/discharge properties were investigated. Their electrochemical properties in terms of cycle performance were also examined.