General oriented assembly of uniform carbon-confined metal oxide nanodots on graphene for stable and ultrafast lithium storage

Abstract

A facile and general method for the oriented assembly of uniform carbon-confined metal oxide nanodots on graphene was developed via a well-designed process including surfactant-induced assembly, mismatched coordination reaction and subsequent in situ carbonization. On the basis of experimental analyses and density functional theory calculations, the key mismatched coordination reaction mechanism is clearly revealed, resulting in the formation of small amorphous metal–ligand complexes. This versatile oriented assembly strategy is then generally applied to obtain various carbon-confined metal oxide (SnO₂, Cr₂O₃, Fe₃O₄ and Al₂O₃) nanodots on graphene. Notably, the as-prepared C@SnO₂@Gr electrode as an LIB anode material possesses a high reversible discharge capacity of 702 mA h g⁻¹ and an excellent capacity retention of over 100% tested at 2 A g⁻¹ after 1200 cycles.