Enhanced cycle performance and synthesis of LiNi0.6Co0.2Mn0.2O2 single-crystal through the assist of Ba ion

Abstract

The single-crystal materials of Ni-based layered oxides have drawn in wide consideration due to excellent cycle performance and storage performance. However, the conditions for synthesizing Ni-based layered oxides with a single-crystal morphology are extremely demanding. In this research, Ba2+ is introduced into the synthesis process of LiNi0.6Co0.2Mn0.2O2 single-crystal material (SC-NCM) to assist the formation of single-crystal materials. Furthermore, this work proposes an inference that the introduction of Ba2+ reduces the diffusion energy at the grain boundaries of the cathode particles, promoting particle coalescence. The role of Ba2+ in this system is investigated using X-ray diffraction, scanning electron microscope, energy-dispersive x-ray spectroscopy, transmission electron microscopy, thermogravimetric analysis and differential thermal analysis. As a consequence, introducing Ba2+ promotes the formation of single crystal morphology and improves the cycle performance of the cathode.