Preparation of LiNi0.8CO0.2O2-based cathode materials for lithium batteries by a co-precipitation method

LiNi0.8Co0.2-xAlxO2 (0 < x < 0.1) cathode powders were prepared with a novel co-precipitation method followed by heat-treating at temperatures between 500 and 900 degrees C. The electrochemical properties as cathode material for lithium batteries were predicted with XRD patterns and examined with capacity retention studies. Among the prepared samples, 800 degrees C heat-treated un-substituted LiNi0.8Co0.2O2 sample showed the best cycling performance. However, the initial specific discharge capacity decreases with increase amount of Al-substitution for the LiNi0.8Co0.2-xAlxO2 powders prepared with the same process. It may due to the increase in the amount of electrochemical inactive Al3+ and the increase in the hindrance of Li+ ions diffusion by increasing Al3+ occupancy of interstitial tetrahedral 6c sites in the Al-substituted cathode materials. (c) 2005 Elsevier B.V. All rights reserved.