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

Abstract

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.