Electrochemically Engineering Antimony Interspersed on Graphene toward Advanced Sodium-Storage Anodes

Nanoengineering of metal anode materials shows great potential for energy storage with high capacity. Zero-dimensional nanoparticles are conducive to acquire remarkable electrochemical properties in sodium-ion batteries (SIBs) because of their enlarged surface active sites. However, it is still difficult to fulfill the requirements of practical applications in batteries owing to the deficiency of efficient and scalable preparation approaches of high-performance metal electrode materials. Herein, an electrochemical cathodic corrosion method is proposed for the tunable preparation of nanostructured antimony (Sb) by the introduction of a surfactant, which can efficiently avoid the agglomeration of Sb atom clusters generated from the Zintl compound and further stacking into bulk during the electrochemical process. Subsequently, graphene as the support and conductive matrix is uniformly interspersed by generating Sb nanoparticles (Sb/Gr). Moreover, the reversible crystalline-phase evolution of Sb ⇋ NaSb ⇋Na₃Sb for Sb/Gr was studied by in situ X-ray diffraction (XRD). Benefiting from the interconnection of the conductive network, Sb/Gr anodes deliver a high capacity of 635.34 mAh g^-1, a retained capacity of 507.2 mAh g^-1 after 150 cycles at 0.1 C (1 C = 660 mAh g^-1), and excellent rate performance with the capacities of 473.41 and 405.09 mAh g^-1 at 2 and 5 C, respectively. The superior cycle stability with a capacity of 346.26 mAh g^-1 is achieved after 500 cycles at 2 C. This electrochemical approach offers a new route toward developing metal anodes with designed nanostructures for high-performance SIBs.