Papers by Author: Kazuya Higeta

Abstract: Spherical Li
Ni1/3Mn1/3Co1/3O2 precursor powders were synthesized by aerosol plasma pyrolysis using aqueous solution of metal nitrate. XRD, SEM, TEM and BET analysis were used for determi- nation of the composition, morphology, particle size and surface area. SEM observation showed that the size of as-prepared particles were about 200 nm. The value of geometrical standard deviation (σg) calculated from the particle size distribution was 1.20, suggesting that the particle size distribution was narrow. The crystal phase of Li
Ni1/3Mn1/3Co1/3O2 was resulted in layered rock salt structure with R3m space group. The rechargeable capacity of Li
Ni1/3Mn1/3Co1/3O2 was about 142-175 mAh/g. The discharge capacity of Li
Ni1/3Mn1/3Co1/3O2 decreased with increasing cycle number. However, the cycling stability of Li(Ni1/3Mn1/3Co1/3)O2 powders that aerosol plasma pyrolysis process offered superior performance to ultrasonic spray pyrolysis process.

Abstract: Homogeneous BaTiO3 nano-sized powders were successfully prepared by spray pyrolysis using multiphase plasma under the air atmosphere. Particle size, morphology, crystal phase and crystallinity of as-prepared powders were characterized by SEM and XRD. The effect of starting precursor solution on the formation of nanoparticles was investigated. The use of Ba/Ti aqueous solution derived from malic acid led to formation of cubic BaTiO3 nanoparticles with 50 nm size.