Cu₇Te₄ as an Anode Material and Zn Dendrite Inhibitor for Aqueous Zn-Ion Battery

Zn metal is a promising anode material for high-energy-density aqueous batteries, but it is plagued by dendrite, low stripping/plating efficiency, and inevitable depletion of active Zn. Herein, a low-intercalation-potential material, Cu₇Te₄, is reported as both an anode material and Zn dendrite inhibitor for aqueous Zn batteries. A low plateau of 0.2 V (vs Zn²⁺/Zn), high capacity of 216 mA h g^–1, and superior cyclability over 4200 cycles can be realized by Cu₇Te₄ anode. Moreover, when Zn is modified with Cu₇Te₄ layer, a hybrid anode based on “intercalation–deposition” mechanism can be ingeniously developed, in which Zn²⁺ ions are sequentially inserted into Cu₇Te₄ and uniformly deposed on Zn at successive low potential. A battery built on such a mechanism sustains more than 1000 h and 1000 times in comparison to less than 100 h and 350 times of a bare Zn. Furthermore, an aqueous “rocking–chair” Cu₇Te₄//ZnI₂ Zn-ion full battery is further demonstrated, which can realize energy densities of 65.3 Wh kg^–1 and 86% capacity retentions after 10 000 cycles. This research contributes to a stable anode material for aqueous Zn batteries and provides an effective strategy to address the Zn dendrite.