Specific Capacity and Capacity Fading of Interstitial and Substitutional Doping of Li in LiNi0.6Co0.3Ti0.1O2 Nano Cathode Material for High Energy Density Li-Ion Battery

Monday, 29 May 2017: 14:40
Grand Salon D - Section 24 (Hilton New Orleans Riverside)
N. Kamarulzaman (Centre for Nanomaterials Research, Institute of Science) and R. Rusdi (Faculty of Applied Sciences,Universiti Teknologi MARA, Centre for Nanomaterials Research,Institute of Science)
Pure and single phase LiNi0.6Co0.3Ti0.1O2, Li1.05Ni0.6Co0.3Ti0.1O2, Li1.05Ni0.55Co0.3Ti0.1O2 materials were successfully prepared using a self-propagating combustion method. The structure and morphology of the materials were characterized using X-Ray Diiffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-Ray Spectroscopy (EDX). The oxidation state of elements and their chemical environments were studied using X-Ray Photoelectron Spectroscopy (XPS). The electrochemical performances of the materials were carried by means of galvanostatic charge-discharge on the fabricated cells. XRD results showed that the materials are impurity-free and single phase with well ordered hexagonal layered structure of R-3m space group. The discharge capacities are between 141 and 145 mAhg-1. The interstitially doped Li1.05Ni0.6Co0.3Ti0.1O2 compound exhibits the highest first cycle capacity of 145.3 mAhg-1 over the voltage range of 2.5 to 4.2 V compared to the undoped sample, LiNi0.6Co0.3Ti0.1O2, showing a capacity of 105.5 mAhg-1. The 70th cycle revealed that the Li interstitially doped material (Li1.05Ni0.6Co0.3Ti0.1O2) shows the highest specific discharge capacity of 132.4 mAhg-1. The capacity fading is only about 8.9% compared to 25.4% for undoped LiNi0.6Co0.3Ti0.1O2 and 10.4% for Li substitutionally doped material (Li1.05Ni0.55Co0.3Ti0.1O2). XPS studies showed that the binding energy of Li 1s is lowest for the best performance compound meaning that the Li+ ions can be extracted more easily from Li1.05Ni0.6Co0.3Ti0.1O2 than the other two materials supporting the electrochemical behaviour of the materials.