Facile synthesis of Tin oxide@2D graphene nanocomposites for enhanced LIB anode materials

Abstract Nanostructured tin oxide (SnO₂) clusters were synthesized through a simple chemical–thermal route and subsequently encapsulated in ultrathin two-dimensional (2D) graphene layers to form SnO₂@graphene nanocomposites for lithium-ion battery (LIB) anodes. While similar composite designs have been explored, the novelty of this study lies in systematically tailoring the annealing process to optimize the interface between SnO₂ and graphene, thereby enhancing electron transport and structural stability during cycling. Structural and surface analyses were performed using SEM, TEM, EDX, XPS, and XRD. The optimized electrode (SG-5) delivered a high gravimetric capacity of 2268 mAh g⁻¹ at 50 mA g⁻¹, retaining 94% capacity after 30 cycles, and an improved rate performance of 576.4 mAh g⁻¹ at 200 mA g⁻¹. The synergistic effect of graphene wrapping and controlled annealing effectively mitigated SnO₂ volume expansion and ensured stable electrochemical performance. These findings provide a new strategy for engineering SnO₂/graphene interfaces via annealing control, offering practical insights into designing robust next-generation LIB anode materials.