SiO_x/C-Ag nanosheets derived from Zintl phase CaSi₂ via a facile redox reaction for high performance lithium storage

As one of the high-capacity anodes in lithium-ion batteries (LIBs), silicon oxide (SiO_x) has attracted wide attention due to its high theoretical capacity, low cost, and proper working voltage. However, the huge volume change and the intrinsic poor conductivity of SiO_x still hinder the practical applications. How to address the issues is the focus of current research. In this work, firstly, hydrogen passivated Si nanosheets (Si₆H₆) were prepared from Zintl phase CaSi₂, then, two-dimensional Ag nanoparticle modified SiO_x/C nanocomposite was prepared via a facile complex redox reaction between Si₆H₆ and AgNO₃-aniline complexing agent. In this design, aniline was served as carbon sources, and Si₆H₆ could be transformed to SiO_x by AgNO₃ in mild solution condition. The obtained Ag modified SiO_x/C (SiO_x/C-Ag) electrode exhibited high specific capacity (550 mAh·g^-1 at 0.6 A·g^-1), superior rate, and cycling performance when served as anode for LIBs.