SiOx/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 (SiOx) 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 SiOx 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 SiOx/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 SiOx by AgNO3 in mild solution condition. The obtained Ag modified SiOx/C (SiOx/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.