High-performance zinc metal anode enabled by large-scale integration of superior ion transport layer

Abstract

Aqueous zinc (Zn) metal battery is regarded as a promising candidate with low cost and high safety for energy storage systems at large scales. However, the destabilized Zn2+ transport at the reaction interface severely restricts the lifespan of zinc anode, and the strategies suitable for large-scale integration of the anode’s protection layer are required. Herein, an independent protective layer of Cu@CuO nanowire arrays is proposed to stabilize zinc anode with comprehensive regulation of Zn2+ transport. Through wet-chemical etching, the nanowire structure with a geometric area of 250 cm2 can be synthesized in one pot. From experimental analysis and simulation results, such a layer not only homogenizes the distribution of interfacial electric field, but also enhances Zn2+ transfer kinetics with improved ionic conductivity and increased transference number. Meanwhile, the activity of hydrogen evolution reaction (HER) is decreased due to the integration of this unique layer. As a result, the protected zinc anode can be stably operated at 2 mA cm−2/2 mAh cm−2, and the stable current density can further increase to 10 mA cm−2. Furthermore, the protective layer is featured with superior hydrophilicity, and can be feasibly utilized for large-area pouch cells, revealing the scalability and effectiveness in practical devices. This work proposes a facile protection strategy for zinc anode from the perspective of optimizing Zn2+ transport by large-scale integration of superior ion transport layer, showing great potential in high-performance zinc metal anode.