Boosting kinetics of tellurium redox reaction for high-performance aqueous zinc-tellurium batteries

Abstract

Aqueous zinc-ion batteries have attracted extensive attention due to their environmental friendliness, low cost and high theoretical capacity. Among them, the conventional cathode materials mainly rely on ion intercalation or surface redox mechanisms, which usually exhibit unsatisfactory specific capacity. Currently, aqueous zinc-tellurium (Zn-Te) batteries based on conversion mechanisms have shown great potential to provide greater specific capacity. However, the sluggish electrochemical reaction kinetics limits the further development of Zn-Te batteries. Herein, the hierarchical structure was prepared by in situ growing MoS2 on N, F co-doped porous carbon nanosheets (MoS2@NFC), which served as Te hosts to construct aqueous Zn-Te batteries. Benefitting from the hierarchical structure and unique catalytic property of the MoS2@NFC, the kinetics of Te redox reaction was remarkably enhanced for aqueous Zn-Te batteries. As a result, the aqueous Zn-Te batteries based the Te-MoS2@NFC electrode exhibited high specific capacity (483 mAh g−1 at 150 mA g−1), outstanding rate performance and excellent cycling stability. Furthermore, the catalytic conversion mechanism of Zn-Te batteries was systematically explored through various ex-situ characterization methods and density functional theory (DFT) calculations. Therefore, this work provides a novel idea to design high performance conversion-type aqueous zinc-ion batteries.