Artificial solid electrolyte interphase coating to reduce lithium trapping in silicon anode for highly stable lithium storage

Abstract

Silicon (Si) has been regarded as a commercially viable anode material because of its outstanding theoretical capacity and rich abundance. However, the poor intrinsic electric conductivity, inherent volume expansion, and lithium trapping problems impede further commercialization. Here, we proposed a dual-design strategy by introducing mesoporous carbon and LiAlO2 as an artificial solid electrolyte interphase (SEI) on Si-based anode. The combination of mesoporous carbon and LiAlO2 both improves the structural stability of the Si-based anode and provides a fast diffusion pathway for lithium ions, thus improving the utilization of lithium. Moreover, thanks to the artificial SEI, the Si anode represent a remarkable electrochemical performance, delivering a specific capacity of 1910.3 mAh g-1 at a current density of 0.2 A g-1 with capacity retention of 73.4% in 140 cycles and prominent rate capability with a discharge capacity of 795.4 mAh g-1 at 1.0 A g-1 in 500 cycles, 456.2 mAh g-1 at 5.0 A g-1 in 1000 cycles.