Synthesis and electrochemical properties of layered Li1.0Mn0.82Ni0.10Ti0.08O2 prepared by chemical lithium insertion

Abstract

The novel LixMnyNizTi1−y−zO2 compounds were prepared by Na+/Li+ ion-exchange and chemical lithium insertion. The eight products were characterized using X-ray diffraction, ICP-AES, SEM, and electrochemical measurements. All the samples were adopted the layered rock-salt type structure. The electrochemical properties of Li0.6Mn0.82Ni0.10Ti0.08O2 sample exhibited the best capacity retention of 87% at 20th charge–discharge test in the voltage range of 1.5 and 5.0 V of all the present samples. The extra lithium was added by chemical lithium insertion using LiI and then fully occupied Li1.0Mn0.82Ni0.10Ti0.08O2 in lithium site was obtained. The initial charge and discharge capacities of Li/Li1.0Mn0.82Ni0.10Ti0.08O2 cell were 250 mAh g−1 and 244 mAh g−1, respectively, with the first coulombic efficiency of 98% between 2.0 and 4.8 V. The graphite/Li1.0Mn0.82Ni0.10Ti0.08O2 cell indicated the first discharge capacity of 208 mAh g−1 at 1.8 V after charging up to 4.7 V. The irreversible capacity loss of 39 mAh g−1 was ascribed to the formation of a solid–electrolyte interface (SEI). The Li1.0Mn0.82Ni0.10Ti0.08O2 is one of the promising materials for positive electrode material in lithium ion batteries for the view point of high capacity and coulombic efficiency.