Cubic Cu2O/Cu2S Particles with a Unique Truncated Edge Structure Anchoring on Reduced Graphene Oxide as An Enhanced Anode Material for Sodium-Ion Batteries

Cubic Cu2O/Cu2S particles with a novel truncated edge structure anchoring on reduced graphene oxide (Cu2O/Cu2S-rGO composites) were synthesized by using a facile growth process. Compared to simple Cu2O cubes and bare Cu2O/Cu2S particles, the Cu2O/Cu2S-rGO composite shows a competitive capacity and stable cyclic stability as anode materials for sodium-ion batteries (SIBs). At a low current density of 60 mA g(-1), the Cu2O/Cu2S-rGO composite delivers an initial discharge capacity of 878.6 mAh g(-1), stable cycling stability of 417.35 mAh g(-1) after 100 cycles, retaining 73.5% of its initial charge capacity, demonstrating a significantly improved cycling reversibility and structural stability. The enhanced electrochemical performance for Cu2O/CuxS-rGO composites might be ascribed to the rGO coating and the breathable structure formed by Cu2O and Cu2S. The outer coated rGO nanosheets could maintain the structural integrity and electrical conductivity, and the main active component (Cu2O and Cu2S) is present in the form of small clusters, providing breathable aggregates capable of effective sequential shrinkage and expansion.