Electrochemical Activation of Carbon-Coated SiO₂ Anode Materials for High-Performance Li-Ion Batteries

A silicon-based anode is one of the most promising anode materials for high-current-density lithium-ion batteries (LIBs). However, the volume expansion of pure Si and the complex synthesis of SiO x make their practical application challenging. On the other hand, SiO 2, as another alternative to Si-based anodes, has attractive properties such as high theoretical capacity, abundance of elements, cost-effectiveness, and high mechanical strength. Nevertheless, due to its intrinsic poor electrochemical activity for lithiation, it is challenging to apply it as an anode. Therefore, to apply SiO 2 as an anode with attractive properties, the electrochemical activation of SiO 2 should be addressed. In this work, a carbon coating of SiO 2 using polydopamine (C@SiO 2 ) and potentiostatic activation of C@SiO 2 are proposed to enhance the electrochemical activity of the C@SiO 2 anode. The C@SiO 2 anode, which is activated into Li 4 SiO 4 and Si phases through hours of potentiostatic procedures, exhibits an excellent reversible capacity of 735.43 mAh g –1 at the 100th cycle. Furthermore, the activated C@SiO 2 anode exhibits excellent full cell performance, indicating its potential application in high-performance LIBs. These results demonstrate that the proposed activation method for C@SiO 2 anode materials can be applied to the preparation of SiO 2 -based anodes with excellent electrochemical performance for high-performance LIBs.