Electrochemical performance of nanostructured LiMxMn2−xO4 (M=Co and Al) powders at high charge–discharge operations

• Published in: Solid state ionics Vol. 176; no. 11-12; pp. 1027 - 1034
• Main Authors: Bakenov, Zhumabay, Taniguchi, Izumi
• Format: Journal Article
• Language: English
• Published: 31.03.2005
• ISSN: 0167-2738
• DOI: 10.1016/j.ssi.2005.02.004

Nanostructured LiMxMn2-xO4(M=Co and Al, 0 < =x < =0.3) powders were successfully synthesized by an ultrasonic spray pyrolysis technique from the precursor solutions; LiNO3, Mn(NO3)2.6H2O and Co(NO3)2.6HzO or Al(NO3)3 - 9HzO were stoichiometrically dissolved into distilled water. The product characteristics such as crystallinity, specific surface area, particle morphology and interior structure of particles, were examined with X-ray diffraction (XRD), the Brunauer-Emmet Teller (BET) method, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), respectively. The chemical composition of the samples was also performed by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The resulting powders were spherical nanostructered particles, which comprised of the primary particles with a few tens of nanometers in sizes. All the samples exhibited a pure cubic spinel structure without any impurities in the XRD patterns, while the surface morphology of as-prepared powders changed from porous to smooth microstructure with the amount of Co or Al substitution. The as-prepared samples were sintered at 750 DGC for 4 h in air. However, the particles morphology and pure spinel phase of nanostructured LiM-rMn2-x04(M=Co and Al)powders did not change after sintering. The as-sintered samples were used as cathode active materials for lithium-ion battery, and electrochemical studies were carried out on the charge/discharge characteristics of the Li/LiMxMn2-xO4(M=Co and Al) cells at room temperature.