Three‐Dimensional Carbon@Fe 2 O 3 @SnO 2 Hierarchical Inverse Opals Arrays as Li–ion Battery Anode with Improved Cycling Life and Rate Capability

We report a novel three‐dimensional (3D) cabon@Fe 2 O 3 @SnO 2 hierarchical composite inverse opals arrays electrode for binder‐free Li‐ion battery anode. In this electrode design, the ordered macroporous SnO 2 acts as conductive skeletons for supporting the 1D Fe 2 O 3 nanorods, offering a high specific surface area and fast pathways for both electron and ion transport, while the carbon coated on the Fe 2 O 3 surfaces works as a buffer layer to improve the conductivity and structural stability. Benefiting from this smart design, the hierarchical carbon@Fe 2 O 3 @SnO 2 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 SnO 2 inverse opals and SnO 2 @Fe 2 O 3 inverse opals electrodes.