A simple method of preparing graphene-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 for lithium-ion batteries

Graphene-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 is synthesized by the spray drying method. The morphology and electrochemical performances of the pristine and graphene-coated cathodes have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), charge–discharge measurements, as well as Ac impedance spectroscopy. At 250 mA g−1, the pristine and graphene-coated samples deliver capacities of ∼141 and 153 mAh g−1 with capacity retention of 80 and 97% in 50 cycles, respectively. An analysis of the charge–discharge capacity values and electrochemical impedance spectroscopy (EIS) measurements reveal that the improved electrochemical performances of the graphene-coated sample are due to the suppression of the solid–electrolyte interfacial (SEI) layer and the enhancement of surface electronic conductivity.

► The Li[Li0.2Mn0.54Ni0.13Co0.13]O2 powders have been coated by graphene. ► Graphene-coated powders have been synthesized by a simple method. ► Cathode material shows excellent electrochemical performance. ► Performance makes this material attractive for large applications.