Synthesis and electrochemical properties of high-density LiNi0.8Co0.2O2 for the lithium-ion-battery cathode

LiNi0.8Co0.2O2 powder with a tap density of 3.23 g cm(-3) has been successfully prepared by a molten-salt synthesis method using a eutectic molten salt of 0.62LiNO(3)-0.38LiOH with a melting point of 175.7 degrees C and Ni0.8Co0.2(OH)(2), where the ratio of Li/(Ni + Cc) is controlled at 1. 1: 1. X-ray diffraction analysis has shown that this material has a well-developed layered structure. Charge-discharge tests have shown that an LiNi0.8Co0.2O2 cathode prepared at 800 degrees C has an initial discharge capacity as high as 163 mAh g(-1) and excellent capacity retention in the range of 3.0-4.3 V at a current density of 0.2 mA cm(-2). (c) 2008 The Electrochemical Society.