Introduction of amorphous TiO2 coating layer to improve the lithium storage of SiO2 nanospheres anode

Silicon dioxide (SiO2) is considered a promising candidate to replace commercial graphite anodes in lithium-ion batteries (LIBs). However, poor electrical conductivity and drastic volume swing hinder it from practical applications. Smart surface coatings have been shown to be good examples of dramatically improved SiO2 cycling performance. Herein, a SiO2@amorphous TiO2 (SiO2@a-TiO2) composite with core–shell structure was synthesized via a facile sol–gel method. The amorphous TiO2 shell shows elastic behavior during lithium discharging and charging processes, maintaining high structural integrity. The resulting materials serve as LIBs anodes with superior lithium storage properties in terms of high initial capacity (1125 m Ah g−1 at 0.1 A g−1), good rate capability (387 m Ah g−1 at 2 A g−1), and excellent cycling stability (582 m Ah g−1 was retained over 300 cycles at 0.1 A g−1).