Artificial interface modification of Ni-rich ternary cathode material to enhance electrochemical performance for Li-ion storage through RF-plasma-assisted technique

Abstract

Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) is a promising high-performance cathode material for large-scale Li-ion storage applications. However, devices consisting of Ni-rich materials are less thermally stable, and several factors hinder their use in practical high-energy–density applications. Herein, an approach for plasma-modified NCM811 with TiN is proposed to effectively improve the electrochemical performance and stabilize the cathode–electrolyte interface reaction. In addition, the following aspects are systematically investigated using different techniques: (i) physicochemical properties; (ii) Li storage performance, particularly, cyclic/rate capacity, kinetic behavior of the lithium-ion diffusivities, and electrical conductivity; and (iii) key factor for improving the electrochemical performance through ex-situ/in-situ investigations. The NCM811-TiN/graphite pouch cell displays a high reversible capacity of 17.5 mAh and sustains over 200 cycles at 1C. Comprehensive characterization and probes indicate that the TiN interface with the NCM electrode enhances thermal stability, cyclic capacity, and rate stability without changing the bulk structure and morphology. Hence, these findings facilitate the practical use of safe and high-energy–density Li-ion batteries.