High performance SiOx anode enabled by AlCl3–MgSO4 assisted low-temperature etching for lithium-ion batteries

Silicon oxide (SiO x ), consisting of nanosized Si crystallites and oxide matrix (SiO y , y near 2), is regarded as one of the most promising anode materials for next-generation high energy density lithium-ion batteries (LIBs). Commonly, modulating oxygen content and surface chemistry are favorable to the lithium ions storage performances of SiO x anode. Here, an AlCl 3 –MgSO 4 assisted low-temperature (250 °C) etching technique is adopted to modify the commercial micron-sized SiO x anode, this novel modification method tunes the O/Si ratio on the surface of SiO x . Impressively, the modified SiO x anode exhibits a high reversible capacity of 480 mAh g −1 at 1A g −1 after 200 cycles and good rate capability of above 110 mAh g −1 at 10 A g −1 . This work provides a simple and feasible modification strategy to the development of high performance SiO x anode.