Electrochemical Properties of 0.6Li2MnO3•0.4Li(Ni0.8Co0.15Al0.05) O2 Composite Nanopowders Prepared by Spray Pyrolysis

Nano-sized composite cathode powders [0.6Li(2)MnO(3)center dot 0.4Li(Ni0.8Co0.15Al0.05) O-2] are prepared by a scalable spray pyrolysis process. The addition of an organic additive into the spray solution is a key factor for the large production of nano-sized composite cathode powders. After post-treatment at high temperatures and a simple milling process, the composite powders prepared from a spray solution with citric acid and ethylene glycol are the size of nanometers. Mean sizes of the powders after posttreatment at 600 and 900 degrees C are 20 and 200 nm, respectively. An ICP analysis determined that the mole ratio of Li/(Ni + Mn + Co) in the powders post-treated at 900 degrees C, is 1.3. The initial charge capacities of the powders post-treated at 600, 700, 800, and 900 degrees C are 357, 341, 338, and 294 mAh g(-1). Their initial discharge capacities are 218, 233, 231, and 240 mAh g(-1). The composite powders post-treated at 900 degrees C have the highest Coulombic efficiency. The discharge capacity of the composite powders post-treated at 900 degrees C decreases from 240 to 229 mAh g(-1) by the 30th cycles, in which the capacity retention is 95.4%.