Electrochemical behaviors of Li[Li (1− x)/3 Mn (2− x)/3 Ni x/3 Co x/3 ]O 2 cathode series (0 < x < 1) synthesized by sucrose combustion process for high capacity lithium ion batteries

Abstract

A mixed cathode material between Li 2MnO 3 and Li[Mn 1/3Ni 1/3Co 1/3]O 2 for high capacity lithium secondary batteries was introduced in this study. It was prepared using the sucrose combustion process because this is a simple process. The oxidation states of Mn, Co and Ni ions in the pristine Li[Li (1− x)/3 Mn (2− x)/3 Ni x/3 Co x/3 ]O 2 compounds were confirmed to be tetravalent, trivalent and divalent, respectively, via XANES measurements. Electrochemical charge/discharge studies showed that the highest first discharge capacity of 224 mAh/g was obtained in composition of x = 0.5 at a 0.2 C rate. The oxidation state of the Co and Ni ions in the Li[Li 1/6Mn 1/2Ni 1/6Co 1/6]O 2 changed to higher oxidation states, but that of the Mn ions did not change.