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

Graphical Cubic composites : Cu 2 O/Cu 2 S-rGO composites are synthesized by using a facile growth process. Benefiting from the rGO coating and the “breathable” structure formed by Cu 2 O and Cu 2 S, the resulting material 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. Cubic Cu 2 O/Cu 2 S particles with a novel truncated edge structure anchoring on reduced graphene oxide (Cu 2 O/Cu 2 S-rGO composites) were synthesized by using a facile growth process. Compared to simple Cu 2 O cubes and bare Cu 2 O/Cu 2 S particles, the Cu 2 O/Cu 2 S-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 Cu 2 O/Cu 2 S-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 Cu 2 O/Cu x S-rGO composites might be ascribed to the rGO coating and the “breathable” structure formed by Cu 2 O and Cu 2 S. The outer coated rGO nanosheets could maintain the structural integrity and electrical conductivity, and the main active component (Cu 2 O and Cu 2 S) is present in the form of small clusters, providing “breathable” aggregates capable of effective sequential shrinkage and expansion.