Double-shell SnO2@Fe2O3 hollow spheres as high-performance anode material for lithium-ion batteries
Construction of novel electrode materials is an effective way to enhance the electrochemical performance of lithium ion batteries (LIBs). In this work, double-shell SnO2@Fe2O3 hollow spheres are fabricated through simple template method. It reveals that the α-Fe2O3 nanorods are heterogeneously assembled on the surfaces of hollow SnO2 spheres. The double-shell SnO2@Fe2O3 hollow spheres, as an anode material for LIBs, demonstrate excellent lithium storage capacity and cycling stability. Their discharge specific capacity decreases to 464 mAh·g-1 at 46th cycles at a current density of 100 mA·g-1, and then increases significantly to 1043 mAh·g-1 up to 190th cycles. Compared with SiO2@SnO2 (221 mAh·g-1 after 190 cycles) and SnO2 (336 mAh·g-1 after 190 cycles) electrodes, the better electrochemical performance of SnO2@Fe2O3 electrode is ascribed to hierarchical hollow urchin-like structure, SnO2@Fe2O3 heterojunctions and oxygen vacancies in α-Fe2O3 nanorods. The sea urchin-like heterostructures dramatically inhibit the agglomeration and prevent the volume expansion during cycling process. This work provides a novel way to construct a promising material with enhanced performance as an anode for LIBs.