Laser pyrolysis synthesis of Si–Sn nanoparticles and Si–Sn@RGO composites as anode materials for lithium-ion batteries

Abstract Silicon–tin (Si–Sn) nanocomposites are viable anode substitutes for lithium-ion batteries (LIBs) as they have the high theoretical storage capacities of lithium (4200 mAh g −1 (Si) and 994 mAh g −1 (Sn)), which are significantly more than those of graphite (372 mAh g −1 ). The Si and Sn cannot be used widely due to their extreme volume expansion during cycling, which results in limited structural stability and quick capacity deterioration. Herein, a nanocomposite based on reduced graphene oxide and nanoparticles containing silicon and tin species (Sn/Si@reduced graphene oxide (RGO)) is presented as a potential solution to mitigate these challenges by incorporating rGO to enhance the electrochemical performance. This nanocomposite demonstrates a high discharge capacity of 1506.91 mAh g −1 at a current density of 0.55 A g −1 after 205 cycles. In contrast, the Sn/Si nanoparticles only kept 125.85 mAh g −1 after the same number of cycles. Sn/Si@rGO nanocomposite improved electrochemical performance due to the conductive network provided by rGO, which adapts to volume variations during cycling and facilitates charge transfer. Results from galvanostatic testing, cyclic voltammetry, and electrochemical impedance spectroscopy support the idea that Sn/Si @rGO nanocomposites could be a high-performance anode material for next-generation LIBs.