Improved electrochemical properties and structural stability of overlithiated Li1+x (Ni1/3Co1/3Mn1/3)1-xO2 prepared by spray-drying method

The electrochemical properties and structural stability of the Li1+x(Ni1/3Co1/3Mn1/3)(1-x)O-2 materials (0 <= x <= 0.17) have been investigated. The materials were prepared using a spray-drying method with the adjusted molar ratios of Li/(Ni + Co + Mn) = from 0.95 to 1.5. The prepared materials exhibited a hexagonal structure in all the region of 0 <= x <= 0.17 and the lattice parameters of the materials gradually decreased as the value of x increased. The discharge capacities of overlithiated material (x = 0.17) was 179 mAh g(-1) at the 50th cycle which is 86% of the initial capacity, whereas the stoichiometric one preserved 77% (141 mAh g(-1)). From the X-ray diffraction results, it was found that the structural stability of charged material was improved by overlithiation, which could contribute to good electrochemical properties of overlithiated materials. (c) 2006 The Electrochemical Society.