Evaluation of Silicon–Graphene Oxide and Silicon Dioxide–Graphene Oxide Composite Anodes for High-Capacity Lithium-Ion Batteries in Terms of Electrochemical Performance

Abstract

Elevated density in energy-advanced anodes is required for LIBs; however, problems like volume growth or reduced capacity make silicon (Si) and silicon dioxide (SiO₂) unsuitable. Using graphene to overcome these real-world constraints, this study compares Si–graphene oxide (Si-GO) and SiO₂–graphene oxide (SiO₂-GO) composite anodes.

The purpose of this study is to elucidate the different performance characteristics of Si-GO and SiO₂-GO anodes. By comprehending these distinctions, silicon-based materials may be rationally designed to meet specific energy density and cycle life needs for new batteries. This will allow for a customized selection or ideal blend of Si and SiO₂ in graphene composites.

A modified Hummer's method is proposed to manufacture graphene oxide (GO). GO is combined with either silicon from magnesiothermic reduction (for Si-GO) or a silica precursor (for SiO₂-GO) to generate composites. The morphology and structure of the materials are examined using elemental analysis, TGA, SEM, XRD, Raman spectroscopy, and XPS. Impedance spectroscopy, rate capability testing, galvanostatic cycling, and cyclic voltammetry are used to assess the electrochemical performance of LiFePO₄-based cells.

Si-GO is anticipated to provide a greater initial specific capacity, and because of its conversion reaction mechanism, SiO₂-GO should exhibit improved long-term cycle stability. Both composites should benefit from graphene's ability to improve electrical conductivity and buffer volume expansion. The trade-off between large capacity and long cycle life will be described in the analysis.

Acknowledgements. This research was supported by the Ministry of Science and Higher Education of the Russian Federation (project No. FSER-2025-0005).