Abstract
This study reports a facile, scalable sol-gel method for synthesizing carbon-coated SnO2-Fe2O3 core-shell nanoparticles (SnO2-Fe2O3@C) designed as high-performance anode materials for lithium-ion batteries. The structural synergy between the SnO2 core and the Fe2O3 shell, combined with an amorphous carbon coating, effectively addresses the issues of severe volume expansion and poor electrical conductivity inherent in metal oxide anodes. X-ray diffraction, transmission electron microscopy, and Raman spectroscopy confirm the successful fabrication of the core-shell structure with a uniform carbon layer of approximately 5 nm. Electrochemical evaluations demonstrate that the SnO2-Fe2O3@C anode exhibits an exceptional specific capacity of 945 mAh g-1 after 200 cycles at a current density of 0.2 A g-1. More importantly, it delivers an outstanding high-rate capability of 480 mAh g-1 even at a high current density of 5.0 A g-1. This superior performance is attributed to the buffer effect of the core-shell architecture, which accommodates mechanical strain during lithiation/delithiation, and the conductive carbon network that accelerates electron transport and stabilizes the solid electrolyte interphase (SEI) layer. This work provides a highly promising and practical strategy for designing advanced transition metal oxide-based anodes for next-generation energy storage applications.
