Thickness-controllable coating on graphite surface as anode materials using glucose-based suspending solutions for lithium-ion battery

Abstract

Surface-passivation is an effective way to allow the anode materials can deliver long-term superior electrochemical performance for lithium-ion batteries (LIBs). Herein, we develop a simple solution suspension-coating method to prepare thickness-controllable nano‑carbon layer (NCL) on a synthesis graphite-mesocarbon microbeads (MCMB) using aqueous glucose solutions with a surfactant-triton X-100 at 25 °C. This simple process can control the thickness of the NCL on MCMB with a range of 1.5–20 nm with various glucose concentrations. The as-formed NCL can reduce the defect sites on MCMB surface and create slightly porous structures within NCL. For electrochemical performance in LIB, we observed that the carbon-coating thickness at around 4 nm shows better reversible capacity (from 295 to 347 mAh g−1), lower Li+ diffusion resistance, stable cycle-life, and superior C-rate performance. As our results, we provide a simple method to stabilize surface properties of MCMB and show better electrochemical performance in LIB. Moreover, this method can be easily exploited in the industrial with a massive production.