Structural and electrochemical characteristics of LiNi_(0.5-x)Co_(2x)Mn_(1.5-x)O_4 prepared by spray drying process and post-annealing in O_2

摘要

LiNi_(0.5-x)Co_(2x)mn_(1.5-x)O_4(0 < = 2x < = 0.2) was prepared by a spray dry process and comparative studies were carried out between the as-prepared series and the series re-annealed in O_2. The cobalt substitution resulted in significant structural and electrochemical variations, such as the transformation of the space group from P4_3 32 to Fd3m, the increase in the occupancy of cobalt in the tetrahedral sites, and the change in the shape of the charge and discharge profiles, which are related to the progressive oxygen loss. Moreover, an improved rate capability and cyclic performance at high rate was observed for the sample with 2x > = 0.1.