Polyhedral Fe3O4 nanoparticles for lithium ion storage

Abstract

Ferroferric oxide, Fe₃O₄, is a highly promising anode material for lithium-ion batteries (LIBs) owing to its excellent electrochemical properties. High resolution transmission electron microscopy (HRTEM) was used to correlate the morphological features of the Fe₃O₄ nanoparticles (NPs) with their electrochemical properties. The co-precipitately synthesized Fe₃O₄ NPs were composed of 14-facet truncated octahedrons containing 6 {100} and 8 {111} planes, and 26-facet polyhedrons containing 6 {100}, 12 {110} and 8 {111} planes, indicating that the shape of NPs is changeable from 14-facet truncated octahedrons to 26-facet polyhedrons. As the anode for LIBs, the NPs delivered a high initial discharge capacity of 1067 mA h g⁻¹, which could be attributed to their small size and abundant exposure of edges and corners in the multi-faceted polyhedral structures, offering low-coordinated atoms that act as active sites for lithium storage.