Effects of Precursor Preparation Methods on the Electrical Properties of Cathode Materials for Lithium Ion Batteries

Abstract

Four kinds of p recursor powders were synthesized from hydroxide coprecipitation and carbonate coprecipitation method s , then the LiNi 1/3 Mn 1/3 Co 1/3 O 2 was prepared by high temperature calcination, and the precipitating agents were sodium bicarbonate, sodium hydroxide (forward and reverse), sodium hydroxide and ammonia. The effects of precur sor preparation methods on the electrical properties of cathode materials for lithium ion batteries were systematically investigated by means of X ray diffraction, scanning electron microscopy and electrochemical performance measurements. The results showe d that the LiNi 1/3 Mn 1/3 Co 1/3 O 2 particles obtained by carbonate co precipitation method were spherical, and the morphology of the precipitated product was similar to that obtained by sodium hydroxide and ammonia. In the voltage range of 3– 4.3 V, the delivered discharge capacities of 1- 1, 1- 2, 1- 3 and 1- 4 at 1C were 147.0, 145.8, 140.2, 138.1 mAh g- 1, respectively. After 50 cycles, the capacity retention ratios were 92%, 89.9%, 85.2%, and 82.1%, respectively.