Layered Cathode Materials Li[Ni[sub x]Li[sub (1/3−2x/3)]Mn[sub (2/3−x/3)]]O[sub 2] for Lithium-Ion Batteries

The structure, synthesis, and electrochemical behavior of layered for 5/12, and 1/2 are reported for the first time. is derived from or by substitution of and by while maintaining all the remaining Mn atoms in the 4+ oxidation state. with can deliver steady capacities of 150 and 160 mAh/g at 30 and 55°C, respectively, between 3.0 and 4.4 V using a current density of 30 mA/g. Differential scanning calorimetry experiments on charged electrodes of for indicate that this material should be safer than with 5/12, and 1/2 can be cycled between 2.0 and 4.6 V to give capacities of about 200, 180, and 160 mAh/g, respectively, at 30°C. with gives a capacity of 220 mAh/g at 55°C between 2.0 and 4.6 V using a current density of 30 mA/g. © 2001 The Electrochemical Society. All rights reserved.