Mesoporous Silicon Microspheres Produced from In Situ Magnesiothermic Reduction of Silicon Oxide for High-Performance Anode Material in Sodium-Ion Batteries

Sodium-ion batteries have been widely used in energy storage owing to its high sodium content and low cost. This study proves that mesoporous silicon microspheres (MSMs) with the homogeneously distributed mesopores ranging from 1 to 10 nm can be used as anodes of NIBs. In situ magnesiothermic reduction of silicon oxide was carried out to synthesize the MSM samples. An anode in NIBs was tested, and it was observed that the MSMs sample which was calcined at 650 °C had a good rate performance of 160 mAh g−1 at 1000 mAg−1 and a high reversible capacity of 390 mAh g−1 at 100 mAg−1 after 100 cycles. Moreover, its long-term cycling performance was 0.08 mAh g−1 decay per cycle for 100 cycles, which was quite excellent. MSMs have high reversibility, good cycling performance, and excellent rate capability, which are related to its ultrafine particle size and mesoporous morphology.