Silicon-carbon synergies for enhanced energy storage: Insights into porous Si/graphite and porous Si/graphene composite anodes

Abstract

This study investigates the structural, morphological, and electrochemical properties of graphite, graphene oxide (GO), reduced graphene oxide (rGO), and porous silicon synthesized via HF:EtOH etching, aiming to optimize their potential as anode materials for lithium-ion batteries. Electrochemical evaluations demonstrated that porous silicon doping significantly enhanced the performance of graphite- and rGO-based anodes. The optimal doping ratios of 20 % for graphite and 10 % for rGO yielded the highest specific capacities and superior cycling stability, as confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode with 20 % porous silicon was able to maintain 99 % of its capacity after 100 cycles at a current density of 1 C. Adding porous silicon to graphene increased the charge-discharge capacity of the electrodes, allowing the electrode with 10 % porous silicon to reach a capacity of 1400 mAh/g.