Electrochemical behaviors of Li [Li(1-x)/3Mn(2-x)/3Nix/3Cox/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(2)MnO(3) and Li[Mn(1/3)Ni(1/3)Co(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(1/6)Mn(1/2)Ni(1/6)Co(1/6)]O(2) changed to higher oxidation states, but that of the Mn ions did not change. (C) 2008 Elsevier Ltd. All rights reserved.