Journal of Power Sources, Vol.269, 31-36, 2014
Synthesis of lithium nickel cobalt manganese oxide cathode materials by infrared induction heating
This study adopts an in-situ infrared (IR) sintering incorporated with carbonization technique to synthesize carbon-coated LiNi1/3Co1/3Mn1/3O2 (LNCM) cathode materials for Li-ion batteries. Compared with electric resistance heating, the in-situ IR sintering is capable of rapidly producing highly-crystalline LNCM powders at 900 degrees C within a short period, i.e., 3 h in this case. Glucose additive is employed to serve a carbon precursor, which is carbonized and coated over the surface of LNCM crystals during the IR sintering process. The electrochemical performance of LNCM cathodes is well examined by charge discharge cycling at 0.1-5C. An appropriate carbon coating is capable of raising discharge capacity (i.e., 181.5 mAh g(-1) at 0.1C), rate capability (i.e., 75.0 mAh g(-1) at 5C), and cycling stability (i.e., capacity retention: 94.2% at 1C after 50 cycles) of LNCM cathodes. This enhanced performance can be ascribed to the carbon coating onto the external surface of LNCM powders, creating an outer circuit of charge-transfer pathway and preventing cathode corrosion from direct contact to the electrolyte. Accordingly, the in-situ IR sintering technique offers a potential feasibility for synthesizing cathode materials commercially in large scale. (C) 2014 Elsevier B.V. All rights reserved.
Keywords:Lithium nickel cobalt manganese oxide;Infrared heating;Carbon coating;Lithium ion battery;Cathode materials