(A) study on the ceramic material processing by ultrasonic spray pyrolysis and electric chemical method

Abstract

\\\\documentclass{article} \\\\usepackage{hfont} \\\\begin{document} LiCoO$_{2}$ powders for lithium secondary battery were successfully prepared by the ultrasonic spray pyrolysis process. In this work, the statistical experimental design method was used to compare the characteristics (particle size, standard deviation, surface area, tab density) of the LiCoO$_{2}$ particles according to the four parameters (synthesis temperature, sintering temperature, sintering time, sintering heating rate). It was found that the optimal synthesis conditions for the synthesis of LiCoO$_{2}$ particles in ultrasonic spray pyrolysis process were as follows; (synthesis temperature: 835 $\\\\sim$ 840 ℃, sintering temperature: 890 $\\\\sim$ 900℃, sintering time: 10 $\\\\sim$ 11hr, sintering heating rate: 580 $\\\\sim$ 590℃ $/$ hr). The above-mentioned optimal conditions were used to prepare the particles with particle size 4.7㎛(standard deviation: $\pm$ 1.3%) and the experimental results were in a good agreement with simulated values. The oxide powders were characterized by scanning electron microscopy, X-ray diffraction, and electrochemical method including charge-discharge cycling. The characteristics as a cathode for lithium ion battery depended on the sintering temperature and sintering time. Consequently, LiCoO$_{2}$ powders made by the ultrasonic spray pyrolysis process displayed a good electrochemical performance and the experimental design method was well applied. The synthesis of spherical hollow silica particles from sodium silicate solution with boric acid or urea as an additive was carried out by ultrasonic spray pyrolysis method. This work dealt with the effect of four parameters (boric acid, urea, feed rate of reactant, and reaction temperature) on particle size and standard deviation. As a result, the mean particle size and standard deviation decreased with increasing of all parameters except urea. In addition, silica particles with ...