Physical and Electrochemical Properties of Spherical Nanostructured LiCrxMn₂₋xO₄ Particles Synthesized by Ultrasonic Spray Pyrolysis

Ultrasonic spray pyrolysis has been successfully applied to the synthesis of partially Cr-substituted lithium manganese oxide (LiCr x Mn 2 - x O 4 (0 ≤ x ≤ 0.3)) particles from the precursor solution; LiNO 3, Cr(NO 3 ) 3 ·9H 2 O, and Mn(NO 3 ) 2 ·6H 2 O were stoichiometrically dissolved into distilled water. The resulting powders were spherical nanostructured particles with a narrow particle size distribution. All the samples exhibited a pure cubic spinel structure in the X-ray diffraction (XRD) patterns. The morphology of as-prepared powders changed from spherical and porous to spherical and dense with an increasing amount of Cr substitution. The densification of particles progressed with the amount of Cr substitution. The as-prepared samples were sintered at 750 °C for 4 h in air and used as cathode active materials for lithium-ion batteries. Test experiments in the electrochemical cells Li|1M LiClO 4 in EC: DEC=1:1| LiCr x Mn 2 - x O 4 demonstrated that the nanostructured LiCr x Mn 2 - x O 4 particles, prepared by the ultrasonic spray pyrolysis and then calcined at 750 °C for 4 h in air, were a promising cathode active material for 4 V lithium-ion batteries at high-charge−discharge and high-temperature operations.