Optimal tailored preparation of Sb/Sb4O5Cl2 nanosheet composite anodes for efficient sodium-ion storage

Abstract

Herein, we report the preparation of Sb/Sb4O5Cl2 nanosheet composites (NSCs) via a galvanic replacement re-action for application as advanced anode materials for sodium-ion batteries. X-ray diffraction and electron mi-croscopy analyses reveal the presence of Sb and Sb4O5Cl2 phases with sheet structures, and amorphous and crystalline regions. The reaction time significantly influences both the sheet size and the amount of amorphous phase in the Sb/Sb4O5Cl2 NSCs. The Sb/Sb4O5Cl2-6 h NSCs exhibits notable electrochemical performance, including high Na-ion storage capacity, high rate capability, and outstanding cycling stability compared to the Sb/Sb4O5Cl2-12 h NSCs. The difference in the electrochemical performances can be assigned to the presence of sheet structures and optimum amorphous phases that act as buffers against the volumetric variation, prevent the destruction of the electrodes during charge/discharge, and improve the reaction kinetics. A full battery consisting of Sb/Sb4O5Cl2||NaxFeFe(CN)6 is developed with an Sb/Sb4O5Cl2-6 h NSC anode and a NaxFeFe(CN)6 cathode. This full battery presents a high working potential of up to 2.45 V, high energy density of 110 Wh kg-1, excellent rate capacity, and stable capability.