Plasma-induced amorphous N-nano carbon shell for improving structural stability of LiNi0.8Co0.1Mn0.1O2 cathode

Abstract

LiNi0.8Co0.1Mn0.1O2 (NCM) materials, which have a high specific capacity and low cost, suffer from large capacity attenuation and poor cycling performance in lithium-ion batteries. It is a straightforward and efficient strategy to elevate cyclic stability by building a stable surface coating to act as a valid physical or chemical barrier. In this study, N-doped carbon-coated active material NCM-N2 was successfully prepared by plasma-enhanced chemical vapor deposition (PECVD) in the N2 atmosphere. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical methods were used to study composition, structure, surface properties, and electrochemical properties. The coated NCM-N2 maintained good cycling performance (210.2 mAh g–1 at 0.1 C after 40 cycles, 188.5 mAh g–1 at 1 C after 100 cycles) and rate ability (131.7 mAh g–1 at 5 C rate). In comparison, the uncoated (NCM) electrode retained only 56.60% of its capacity (102.5 mAh g–1 at 1C after 100 cycles). The plasma-induced amorphous N-nano carbon shell on the surface of NCM effectively isolated the electrode from the electrolyte vastly inhibiting the occurrence of side reactions and was beneficial to the improvement of electronic conductivity. The plasma-induced amorphous N-nano carbon shell has great potential for enhancing the structural stability of Ni-rich ternary cathode materials, with broad application prospects in the Lithium-ion battery industry.