Synthesis and Electrochemical Characterization of a Li-Rich Li_1.17Ni_0.34Mn_0.5O₂Cathode Material for Lithium-Ion Cells

Abstract

Lithium-rich layered cathodes have emerged as fascinating materials for high energy density lithium-ion cells owing to their high working voltage window and specific capacity. Herein, we report a novel high-capacity Li-rich cathode material having the composition Li1.17Ni0.34Mn0.5O2 synthesized through a simple carbonate co-precipitation method without using any chelating agents. Inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) coupled with energy-dispersive spectroscopy (EDS) were employed to characterize the chemical composition, structure, morphology, and elemental distribution, respectively of the synthesized cathode material. The XRD results revealed a well-defined layered structure, and the SEM images show a porous structure, which is beneficial for electrolyte infiltration and easy lithium-ion diffusion. The material delivered an initial discharge capacity of 250.3 mAhg–1 at C/10 rate and exhibited excellent cycling stability (capacity retentions of >98% at C/10 and >90% at 1C rates at the end of 100 and 200 cycles, respectively). Rate capability studies show that the material delivers discharge capacities of 242.3 mAhg–1 at C/5, 220.1 mAhg–1 at C/2, 183.7 mAhg–1 at 1C, and 131.5 mAhg–1 at 2C rates. The excellent electrochemical performance of this cobalt-free high capacity Li-rich cathode material makes it a promising candidate for high energy density lithium-ion cells.