Faceted Cu2O structures with enhanced Li-ion battery anode performances

Abstract

Micro- and nanocrystals with different facets may exhibit different chemical activities that are of great importance in practical applications. The electrochemical performances of Cu₂O anodes with different crystal planes are compared. This work comprehensively investigates the effect of the crystal plane on the electrochemical performance of Cu₂O. Firstly, Cu₂O polyhedra with different morphologies, i.e., cube, octahedron and truncated octahedron, with different degrees of exposed {110} facets, were synthesized. Cu₂O cubes show the highest capacity among these Cu₂O polyhedra. The present results prove that the {100} facets of Cu₂O display high electroactivities toward redox reactions. The electroactivity sequence of the crystal planes is {100} > {111} > {110}. These results confirm that the additional capacity of Cu₂O is due to the generation of CuO, which can conduct a two-electron redox reaction. The anode performances of Cu₂O polyhedra are dependent on planes, and this can provide a novel route to design high performance electrode materials for lithium-ion batteries.