Double‐confined nanoheterostructure Sb/Sb <sub>2</sub> S <sub>3</sub> @Ti <sub>3</sub> C <sub>2</sub> T <sub> <i>x</i> </sub> @C toward ultra‐stable Li‐/Na‐ion batteries
Dan Wang, Qun Ma, Huan He, Zhiyuan Wang, Runguo Zheng, Hongyu Sun, Yanguo Liu, Chunli Liu
Abstract
Abstract Antimony‐based materials with high capacities and moderate potentials are promising anodes for lithium‐/sodium‐ion batteries. However, their tremendous volume expansion and inferior conductivity lead to poor structural stability and sluggish reaction kinetics. Herein, a double‐confined nanoheterostructure Sb/Sb 2 S 3 @Ti 3 C 2 T x @C has been fabricated through a solvothermal method followed by low‐temperature heat treatment. The dual protection of “MXene” and “carbon” can better accommodate the volume expansion of Sb/Sb 2 S 3 . The strong covalent bond (Ti–S, Ti–O–Sb, C–O–Sb) can firmly integrate Sb‐based material with Ti 3 C 2 T x and carbon, which significantly improves the structure stability. In addition, the carbon layer can restrain the oxidation of MXenes, and the nano‐Sb/Sb 2 S 3 can facilitate electron/ion transport and suppress the restacking of MXenes. The heterogeneous interface between Sb and Sb 2 S 3 can further promote interfacial charge transfer. The MXene‐Sb/Sb 2 S 3 @C‐1 with the optimal Sb content shows high specific capacities, comparable rate properties and ultra‐stable cycling performances (250 mAh·g −1 after 2500 cycles at 1 A·g −1 for sodium‐ion batteries). Ex situ X‐ray diffractometer (XRD) test reveals the storage mechanism including the conversion and alloying process of MXene‐Sb/Sb 2 S 3 @C‐1. Cyclic voltammetry (CV) test results demonstrate that the pseudocapacitance behavior is dominant in MXene‐Sb/Sb 2 S 3 @C‐1, especially at large current. This design paves the way for exploring high‐performance alloy‐based/conversion‐type anode for energy storage devices.