Effect of BaSO4 additive on cycling performance of ZnS/C–SnO2 for advanced sodium-ion batteries

Abstract

Tin dioxide (SnO2), because of its excellent theoretical capacity (1378 mAh·g−1) in sodium-ion batteries, is a promising anode material for sodium-ion batteries. However, the large volume expansion of tin oxide during the cycle will lead to severe electrode pulverization and affect battery performance. Herein, SnO2 was successfully purified from tin slime and ball milled with ZnS/C, which was prepared by hydrothermal. The synergistic effect of ZnS and SnO2 bimetallic composite was used to buffer the volume expansion. Moreover, it is surprising to find BaSO4 additive can effectively inhibit the volume expansion, and the ZnS/C–SnO2 with 5 wt% BaSO4 showed favorable electrochemical performance. The discharge specific capacity remains at 301 mAh·g−1 at 50 mA g−1 after 50 cycles and 68.8 mAh·g−1 at a high current density of 1600 mA g−1. A series of tests shows that the introduction of BaSO4 can maintain the structure of ZnS/C–SnO2, thereby avoiding the fracture of the electrode due to volume expansion.