Electrochemical Properties of C/SiO2/Graphene Nanoplatelets as High-Rate Performance Anode Material in Li-Ion Batteries

Abstract

Lithium-ion batteries are vital power sources for modern society, especially mainly powered electronic devices, electric vehicles (EVs), and future stationary energy storage. Battery cost is still challenging for EVs and large-scale applications that continuously require the development of low-cost and abundant elements-based materials for sustainable battery manufacturing. SiO₂ derived from rice husks emerges as a promising anode material owing to its advantageous raw source and cost-effectiveness. However, the material's low electronic conductivity and poor lithium-ion diffusion rate make it unsuitable for fast-charging or high-power applications. To overcome these challenges, graphene nanoplatelets have been introduced as a conducting additive to enhance electronic conductivity and optimize lithium diffusion in the battery. In this research, an ultrasonic method was utilized to create a composite of C/SiO₂/graphene using C/SiO₂ derived from rice husk and graphene nanoplatelets. The mixture containing 85 wt% of graphene exhibited superior electrochemical performance among the investigated ratios with excellent cycling performance (305 mAh g⁻¹ with capacity retention of 86.18% after 50 cycles at 0.1 A g⁻¹) and an impressive rate capability (69.9 mAh g⁻¹ at a high current of 2.0 A g⁻¹, nearly three times higher than the bare C/SiO₂). XPS and GITT analysis confirmed that the solid electrolyte interphase (SEI) layer on the C/SiO₂/graphene electrode was more stable and conductive due to higher LiF-Li₂CO₃ content, which enhanced the lithium diffusion from the graphene's high surface area.