Green Synthesis of Graphene Flake/Silicon Composite Anode for Lithium-Ion Batteries Using a Ball-Mill-Derived Mechanical Transfer Technique

Graphene, recognized for its impressive strength, flexibility, and conductivity, has garnered significant interest for numerous applications. Within energy storage sector, especially in battery technology, graphene shows promise for improving battery component performance. Graphene/silicon composites in lithium-ion batteries are gaining attention for their potential to overcome some of the challenges associated with silicon as a high-capacity anode material. Here we present an eco-friendly approach to fabricate graphene flakes, utilizing ball milling, ultrasonication, and spray drying to enable efficient mechanical transfer of graphene onto silicon particles. The technique employs a combination of dry/wet exfoliation and self-assembly, effectively eliminating the need for hazardous chemicals. The developed method illustrates the successful integration of silicon within a graphene envelope, resulting in a stable core-shell structure. Characterization techniques, such as scanning electron microscopy, tunneling electron microscopy, X-ray diffraction, and Raman spectroscopy, verify the quality and stability of the composite with graphene. Electrochemical assessments demonstrate that the composite composed of silicon wrapped in graphene has enhanced cycle stability when compared to pure silicon. Cross-sectional analysis of the microstructure reveals reduced volume expansion and improved structural stability of the electrode. This green synthesis method toward fabricating graphene-based composites holds enormous potential for promoting sustainable manufacturing practices.