The effect of adding graphene nanoparticles to the thermal performance of LiCo0.525Ni0.475O2 cathode materials in Li-ion batteries

Abstract

In this work, the effect of adding graphene to the performance of layered LiCo0.525Ni0.475O2 (LCNO) cathode materials was investigated. Cathode materials LiCo0.525Ni0.475O2 (LCNO) were prepared using a self-propagating combustion reaction. Graphene (G) was added to the prepared compound (LCNO) in different weight percentages to obtain LCNO/G (LCNOG) to improve cathode performance. The powder was divided into four parts weighing 10 g each, and the parts were mixed with percentages weighing 0, 0.5, 2, 4 and 6% of graphene with 200 ml of ethanol; they were then stirred several times at room temperature to dry completely The effect of graphene weight percentages on LCNOG mass loss was studied using thermo-gravimetric analysis (TGA). It was concluded that all of the added percentages of graphene behaved the same in all temperatures, except for 6% added graphene, where it demonstrated inverse behaviour at a high temperature. To determine the optimum annealing temperature range, TGA was identified at 650, 750 and 850 °C for 12 hours in the air. The X-ray diffraction (XRD) patterns of the LCNO and LCNOG showed the crystallisation of all powders in the space group R-3m and hexagonal axes for the crystal system. Energy dispersive spectrometry (EDS), field emission scanning electron microscopy (FE-SEM), a vibrating sample magnetometer (VSM) and atomic force microscopy (AFM) were also used. The LCNOG surface morphology consisted of regular coverage of nano-crystalline grains and random orientation.