Pre-lithiation synergized with magnesiothermic reduction to enhance the performance of SiO anode for advanced lithium-ion batteries.

Due to its high theoretical specific capacity, micron-sized silicon monoxide (SiO) is regarded as one of the most competitive anode materials for lithium-ion batteries with high specific energy density. However, originating from the low initial Coulombic efficiency (ICE) and large volume expansion, its large-scale application is seriously hindered. Herein, an easy-to-implement solid-state pre-lithiation method synergized with the magnesiothermic reduction process was performed to enhance the ICE of SiO and a common bimetallic hydride was used as a prelithiation reagent. Moreover, the effects of different pre-lithiation reagent amounts on the physical and electrochemical properties of SiO are investigated. Notably, the SiO-LA@C composite anchored by in-situ generated LiAl(SiO) shows a more stable microstructure and excellent electrochemical properties, which delivers an ultrahigh ICE of 89.4 % and an excellent initial capacity of 1864.4 mAh g. Furthermore, the full cells were successfully assembled by using the prepared anodes, which exhibit relatively stable cycle performance over 150 cycles. This work suggests a safe and feasible route to enhance the ICE of SiO for the applicable SiO-based anode materials.