Rational design of zinc powder anode with high utilization and long cycle life for advanced aqueous Zn–S batteries

Aqueous zinc-sulfur (Zn-S) batteries are regarded as excellent candidates for energy storage applications due to their low cost, non-toxicity, and high theoretical energy density. However, the low utilization of the traditional thick foil-type Zn anode would severely restrict the overall energy density of Zn-S batteries. Herein, a mechanically and chemically stable powder-Zn/indium (pZn/In) anode with finite Zn loading was designed and constructed for enhancing the cycle stability of aqueous Zn-S batteries. Notably, the bifunctional In protective layer can inhibit the corrosion rate of highly active pZn and homogenize the Zn²⁺ flux during Zn plating/stripping. As a result, the obtained pZn/In anode exhibits a greatly improved cyclability of over 285 h even under a much harsh test condition (10 mA cm^-2, 2.5 mA h cm^-2, Zn utilization rate: ∼38.5%). Furthermore, when assembled with an S-based cathode at a negative/positive (N/P) capacity ratio ∼2, the full cell delivers a high initial specific capacity of ∼803 mA h g^-1 and operates stably for over 300 cycles at 2C with a low capacity fading rate of ∼0.17% per cycle.