Graphene‐Oxide‐Encapsulated Fe2O3 Nanoparticles with Different Dimensions as Lithium‐Ion Battery Anodes: The Morphology Effect of Fe2O3

Abstract Fe 2 O 3 is expected to be a favorable candidate to replace commercial graphite as anode for lithium‐ion batteries (LIBs), however, it is impeded by dramatic volume expansion during charge/discharge process. Morphology control strategies have been widely conducted to develop the tolerance of Fe 2 O 3 against the volume change. To investigate the morphology effect, herein, graphene oxide (GO) encapsulated Fe 2 O 3 nanoparticles with three microstructures of nano‐rods, nano‐sheets, nano‐polyhedrons were synthesized. The structure‐dependent electrochemical performance has been demonstrated. The 1D rod‐like nano‐Fe 2 O 3 alleviates the inherent wrinkle morphology of GO sheets, which construct a stable three‐dimensional composite structure. Therefore, the GO‐encapsulated rod‐shaped Fe 2 O 3 (Fe/GO‐r) exhibits excellent reversible capacity of 1168.3 mA h g −1 over 100 cycles at 200 mA g −1 . The investigation of lithium‐ion migration kinetics indicates that Fe/GO‐r presents the highest contribution rate of surface induced capacitance. This study contributes towards the design of well‐performing anode materials for LIBs by investigating the effect of material morphologies.