A facile method to synthesize carbon coated Li1.2Ni0.2Mn0.6O2 with improved performance

Graphical abstract: Li1.2Ni0.2Mn0.6O2 powders are synthesized and then coated by decomposed carbon. The discharge capacity of carbon-coated cathode at 0.1 and 5 C are 246 and 125 mAhg−1, while those of ball-milled cathode are 222 and 49 mAhg−1. - Highlights: • A simple method was applied to synthesize carbon-coated Li1.2Ni0.2Mn0.6O2. • The discharge capacities of carbon-coated sample at 0.1 and 5.0 C rates are 246 and 125 mAh/g. • Capacity retention of carbon-coated electrode after 50 cycles is 97.5%. - Abstract: Carbon-coated Li1.2Ni0.2Mn0.6O2 powders have been synthesized with Bakelite and heat process in air. The effect of carbon coating on the physical and electrochemical properties have been discussed through the characterizations of X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), discharge and rate tests. The carbon-coated cathode exhibits much improved first discharge capacity and rate capability than the pristine sample. The discharge capacity at 0.1 and 5.0 C rates are 246 and 125 mAhg−1, while that of pristine are only about 222 and 49 mAhg−1, respectively. The capacity retention of Li1.2Ni0.2Mn0.6O2 electrode after 50 cycles is improved from 89.8 to 97.5% after carbon coating. EIS results indicate that Rct of Li1.2Ni0.2Mn0.6O2 electrode is decreased from 62 to 37 Ω after carbon coating