The investigation of Ti-modified LiCoO_2 materials for lithium ion battery

摘要

EDAX measurement reveals that the atomic ratio of Ti/(Ti + Co) is much higher than the mole feed ratios in the preparation for the LiCo_(0.99)Ti_(0.01)O_2 material. XPS observation further tells that in LiCo_(0.998)Ti_(0.002)O_2 phase with quite low Ti amount, almost no Ti can enter into the LiCoO_2 lattice, it is more inclined to enrich in the particle surface. Electrochemical examinations show that the cycling stability of LiCo_(0.998)Ti_(0.002)O_2 is as good as that of LiCoO_2/LiCo_(0.99)Ti_(0.01)O_2 composite between 3.0 and 4.3 V, and the latter has a better rate performance. It is considered that the difference of the high rate performance between the Ti-modified LiCoO_2 materials is more likely to originate from the different particle characteristics, when their Ti amounts are low enough.