Synthesis and characterization of high-performance RGO-modified LiNi0.5Mn1.5O4 nanorods as a high power density cathode material for Li-ion batteries

Micronanosized LiNi0.5Mn1.5O4 nanorods coated with reduced graphene oxide is successfully synthesized by a hydrothermal-assembly method. The as-prepared samples are characterized by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscope, and electrochemical tests. The XRD and Raman results show that the LiNi0.5Mn1.5O4 nanorods have disordered structure of Fd-3m space group. The SEM characterization exhibits that LiNi0.5Mn1.5O4 nanorods are about 200-400nm in diameter, and the RGO is well dispersed on the surface of LiNi0.5Mn1.5O4 nanorods. Moreover, a RGO layer coated on the surface of LiNi0.5Mn1.5O4 can suppress the interfacial side reactions. The electrochemical tests show that the RGO-LNMO composites reveal high specific capacity and excellent cyclic stability at high rates. The 1%-RGO-LNMO composite can still possess the capacity of 71.4mAhg(-1) and excellent capacity retention about 99% after 1000cycles at 10C rate. The excellent performance of RGO-LNMO composites makes it a promising candidate as lithium-ion battery cathode materials.