Revealing the Role of Topotactic Anion Exchange in the Robust Zn Ion Storage of CuS1–xTex

Abstract

Rechargeable aqueous zinc-ion batteries (ZIBs) exhibit significant potential for next-generation energy storage technologies, yet their development is hindered by Zn metal anode challenges, such as dendrites and parasitic reactions. Herein, an anionic Te-substitution CuS (CuS_1–xTe_x) is put forward as a promising conversion-type Zn-metal-free anode for aqueous ZIBs. The Te substitution tailors the electronic structure of CuS and enhances the conductivity. The synergistic effect endows the CuS_1–xTe_x anode with a higher capacity up to 274 mA h g^–1 at 0.1 A g^–1 than that of pure CuS (100 mA h g^–1). An aqueous “rocking-chair” CuS_1–xTe_x//MnO₂ Zn-ion full battery is demonstrated, which provides a high specific capacity of 109 mA h g^–1.