Sandwich-like heterostructured SnSb/MXene composite anode for enhanced sodium-ion storage performance

Alloy-type SnSb is regarded as a potential candidate of Na-ion host material because of its high theoretical capacity achieved through reversible redox reactions. However, the drawbacks associated with massive volume variations limit its practical application. In this study, sandwich-like heterostructured composites composed of multilayered MXene and SnSb nanocrystals were prepared via a simple wet-chemical pre-cipitation method. The multilayered MXene with mechanical robustness and high electrical conductivity helped to accommodate the severe volume changes of SnSb nanocrystals, and provide a sufficient con-ductive network that facilitated electron and Na-ion transportation, and participate in electrochemical reactions through its capacitive behavior. The uniformly embedded SnSb nanocrystals in the interlayer of MXene prevented the re-stacking of the MXene multilayer upon cycling. The SnSb/MXene composite anode exhibited remarkable reversible capacity (398 mAh g-1 at 100 mA g-1) with dramatically improved Na-ion storage performance regarding cyclability and rate capability compared to pure SnSb anodes. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).