Three-Dimensional Carbon@Fe2O3@SnO2 Hierarchical Inverse Opals Arrays as Li-ion Battery Anode with Improved Cycling Life and Rate Capability

We report a novel three-dimensional (3D) cabon@Fe2O3@SnO2 hierarchical composite inverse opals arrays electrode for binder- free Li-ion battery anode. In this electrode design, the ordered macroporous SnO2 acts as conductive skeletons for supporting the 1D Fe2O3 nanorods, offering a high specific surface area and fast pathways for both electron and ion transport, while the carbon coated on the Fe2O3 surfaces works as a buffer layer to improve the conductivity and structural stability. Benefiting from this smart design, the hierarchical carbon@Fe2O3@ SnO2 composite inverse opals electrode as a Li ion battery anode exhibits a high discharge capacity of 1021 mAh/g at a current density of 100 mA/g, better cycling life (capacity retaining at 388 mAh/g after 200 cycles) and excellent rate capability, which is superior to those of individual SnO2 inverse opals and SnO2@Fe2O3 inverse opals electrodes.