Enhanced reversibility and cyclic stability of biomass-derived silicon/carbon anode material for lithium-ion battery

Abstract

Silicon as an anode material for lithium ion batteries (LIBs) has drawn wide attention due to exhibiting ten times theoretical capacity than graphite. However, the large reversible capacity loss resulting from the continuous formation of solid-electrolyte interphase (SEI) film and the collapse of the electrode structure hinders the application. Herein, rice husk-derived nano silicon was coupled with N-doped carbon originated from pyrrole. The obtained nano Si/C material demonstrates superior cycling stability but still a relatively low initial coulombic efficiency of 72.0%, which can be boosted to 95.1% by prelithiating with stabilized lithium metal powder (SLMP). The prelithiated Si/C electrode can maintain the structural integrity during Li intercalation/deintercalation process owing to the synergistic effect of N-doped carbon coating layer and excellent electrode interface ascribed to the formation of stable SEI film in the prelithiation stage, contributing to a reversible capacity of up to 1247.8 mAh g−1 with 92.4% capacity retention over 50 cycles. The strategy has a great potential in the area of sustainable chemistry and energy storage system.