Improved structural stability of Ni-rich cathode materials via simple dry process for Li-ion Batteries

Abstract

I reported that highly stable LiNi0.8Co0.1Mn0.1O2 (that is, NCM) via a simple and one-step dry surface treatment approach (that is, G-NCM). The cobalt precursor was coated on the surface of the bare NCM in purpose to improve the material integrity by protecting the cathode surface against the acidic species attack. Furthermore, the transition metal (TM) concentration gradient in the primary particles ensured the structural stability by suppressing the evolution of micro-crack in the cathode particles and reducing transition metal dissolution. The more important thing was the enhanced material integrity allowed stable and uniform solid electrolyte interphase (SEI) layer on the graphite anode, leading to unprecedented full-cell performance. After the surface treatment, the high temperature (45 oC) cycle performance was improved from 20 % for bare NCM to 50 % for G-NCM. During the cycle, the G-NCM retained higher average coulombic efficiency of ~99.8 % than that of the bare NCM (~98.5 %). The electrochemical performance was prepared by full-cell. This finding could be a breakthrough for the LIB technology, providing a rational approach for the development of advanced cathode materials.