Microwave-reduced graphene oxide wrapped NCM layered oxide as a cathode material for Li-ion batteries

Nanocrystalline Li(Ni1/3Co1/3Mn1/3)O-2 (NCM layered oxide) was synthesized through the solution combustion route to use as the cathode material in the Li-ion battery. Reduced graphene oxide (RGO) was employed as the additive to improve electrochemical performance of the battery. Graphene oxide was reduced by microwave irradiation. The RGO was wrapped around the NCM when added in different weight fractions to fabricate nanocomposite mixtures for use as the cathode of the LIB. The initial charge//discharge capacities of NCM and NCM-5 wt.% RGO were measured at a rate of 0.05C in the voltage window of 2.5-4.3 V at room temperature and showed values 198.1/1167.6 mAh/g and 209.2//186.6 mAh/g, respectively. The capacity retention of the optimum graphene-containing cathode during the cycling testing at different C rates increased to 99.6% as compared to that of pristine NCM cathode being 94.7%. Impedance spectroscopy studies revealed that graphene additive caused a decrease in the charge transfer resistance and an increase in the Li-ion diffusion coefficient. (C) 2020 Elsevier B.V. All rights reserved.