Interfacial Bonding of SnSb Alloys with Graphene Toward Ultrafast and Cycle-Stable Na-Ion Battery Anodes

Alloy-type materials have aroused wide concern as potential anodes for Na-ion batteries (NIBs) because of their high theoretical capacities and suitable Na-storage potentials. Fabricating composites with carbon matrixes is the most common strategy to solve their key issues of large volume expansion and sluggish reaction kinetics. However, it is still challenging to achieve strong interfacial interaction between alloy-type materials and carbon matrixes, thus largely improving the buffering effect of carbon matrixes on volume change. Herein, we have developed a SnSb-graphene (SnSb-G) hybrid anode with interfacial Sn/Sb-C bonding via a plasma-assisted mechanochemical method. The Sn/Sb-C bonding can enhance the interfacial interaction between SnSb and graphene, which inhibits the detachment of SnSb nanoparticles from graphene upon cycling and promotes the buffering effect of graphene. Meanwhile, the strong interfacial bonding of conductive graphene network to SnSb nanoparticles can greatly facilitate the Na+ storage/transfer along the SnSb/graphene interface, rendering electrode superior performance at high rates. Therefore, as an anode for NIBs, the SnSb-G composite exhibits superb rate capability (301.5 mAh g-1 at 10.0 A g-1) and cyclic stability (85.8%/89.1% capacity retentions at 1.0/2.0 A g-1 after 1000 cycles). Moreover, the assembled full cell delivers a high energy density of 145 Wh kg-1 and superior cycling performance of 333.6 mAh g-1 after 200 cycles, demonstrating its potential for practical application. This work provides new insight to achieve high-performance alloy-type anodes for practical NIBs.