Oriented Zn(0 0 2) planar plating/stripping for high-capacity ultralong-life aqueous batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) are facing the challenges of low stability of Zn anodes with dendrite growth and hydrogen evolution reaction in promoting commercial applications. We report herein a dual-configuration bifunctional DL-citrulline (DL-Cit) as an electrolyte additive to stabilize Zn anodes for ultralong cycle-life aqueous energy storage. Trace amounts of DL-Cit reconstruct the solvation structure of Zn²⁺ via strong interactions with Zn²⁺, while DL-Cit is preferentially adsorbed on Zn anode surfaces to orchestrate the ion flux and ensure uniform Zn deposition. The well-formed flat Zn(0 0 2) texture not only enhances the electrochemical stability of Zn anodes but also exhibits more significant orientation priority upon increasing current density. These properties endow Zn anodes with an average coulombic efficiency of 99.7% after 1500 cycles and a long cycle life of over 3000 h, achieving an ultrahigh cumulative plating capacity of 4.8 Ah cm⁻² even under rigorous plating/stripping conditions (8 mA cm⁻²). Consequently, the Zn||MnO₂ full cells provide a high capacity of 143.35 mA h g⁻¹ after continuous cycling for more than 3000 cycles. The Zn||activated carbon hybrid capacitors with DL-Cit additives operate stably beyond 30,000 cycles. This versatile electrolyte strategy provides an effective solution for the practical application of Zn-based energy storage devices.