Enhanced electrochemical performance of polyacene coated LiMn2O3.95F0.05 for lithium ion batteries

LiMn2O3.95F0.05 is coated by a thin polyacene (PAS) layer through calcining and rapid cooling using phenol formaldehyde resin as precursor. The effect of the PAS coating on discharge cycling performance of LiMn2O3.95F0.05 spinel powder is investigated in the range of 3.0-4.35 V at 1 C. Powder X-ray diffraction pattern of the PAS coated spinel LiMn2O3.95F0.05 shows that the PAS coating does not affect the structure and purity of spinel. Scanning electron microscopy (SEM) and Transmission electron microscope (TEM) images show that the LiMn2O3.95F0.05 with a perfect shape of spinel is obtained and PAS is homogenously distributed on the surface of LiMn2O3.95F0.05 powder particles. According to the results of TEM and Fourier transform infrared spectroscopy (FTIR), PAS layer is coated on the surface of LiMn2O3.95F0.05 successfully. The electrochemical performances of LiMn2O3.95F0.05 prepared in this manner shows to be positively affected by the PAS coating layer, showing good cyclic stability and high diffusion coefficient of lithium ions. (C) 2013 Elsevier B.V. All rights reserved.