Polyhedral Fe3O4 nanoparticles for lithium ion storage

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.