Abstract
Development of high performance cathode materials, layer-structured ternary LiNi x Co y M 1-x-y O 2 cathode materials have attracted much attention owing to their larger capacity and higher energy density.Persistent efforts have been devoted to tackling certain issues like low electronic conductivity and poor structural stability. Dual strategy of Mg doping and surface modification of the cathode material was adopted to improve the performance of the battery. Fullerene-Multi-Walled Carbon Nanotube (MWCNT) hybrid draped LiNi 0.1 Mg 0.1 Co 0.8 O 2 nanocomposite was synthesized by a simple chemical route. The fullerene-MWCNT hybrid modifies the surface of pristine LiNi 0.1 Mg 0.1 Co 0.8 O 2 thereby improves the electrochemical performance and maintains the structural stability of the cathode material. Pristine LiNi 0.1 Mg 0.1 Co 0.8 O 2 and LiNi 0.1 Mg 0.1 Co 0.8 O 2 / fullerene-MWCNT nanocomposite were studied using various advanced characterization techniques such as X-ray diffraction (XRD), Micro-Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), and High-Resolution Transmission Electron Microscopy (HRTEM). It is found that LiNi 0.1 Mg 0.1 Co 0.8 O 2 particles retain their structural integrity after being enveloped with a fullerene-MWCNT hybrid. The electrochemical performance was investigated with cyclic voltammetry(CV), galvanostaticcharge-discharge(GCD) test and electrochemical impedance spectroscopy(EIS). As prepared LiNi 0.1 Mg 0.1 Co 0.8 O 2 , when deployed in the form of LiNi 0.1 Mg 0.1 Co 0.8 O 2 / fullerene-MWCNT composite exhibits a high specific capacity of 208 mAh g -1 .Fullerene-MWCNT hybrid draped LiNi 0.1 Mg 0.1 Co 0.8 O 2 nanocomposite provides an effective Li + and electron channel that significantly increased the Li-ion diffusion coefficient and reduced the charge transfer resistance. Besides,the lithium diffusion coefficient increased from 5.13 x 10 -13 (Li/LiNi 0.1 Mg 0.1 Co 0.8 O 2 ) to 8.313 x 10 -13 cm 2 s -1 due to the improved kinetics of Li insertion/extraction process in Li/LiNi 0.1 Mg 0.1 Co 0.8 O 2 +fullerene-MWCNT cell.
Enhanced Electrochemical Performance of LiFePO4 Cathode Material Promoted
by CdO and Carbon Co-Coating
