N‐Doped Ti3C2Tx Interfacial Layer Enabling Uniform Zn Deposition along (002) Plane for Stable Aqueous Zinc‐Ion Battery

Abstract

AbstractAqueous zinc‐ion batteries hold great potentials for large‐scale grid energy storage. However, the electrode corrosion, hydrogen evolution, and dendrite growth of Zn anode often lead to cell failure. Herein, N groups in Ti3C2Tx (NMXH) are introduced as interfacial layer through hydrothermal treatment of Ti3C2Tx with urea. The experimental analysis and density functional theory calculation indicate that N groups in Ti3C2Tx can homogenize electric field distribution, promote adsorption of Zn2+ on N groups, and strength interactions between N groups and Zn atoms on (002) plane. Thereby, the use of NMXH interfacial layer can effectively suppress the side reactions and realize uniform Zn deposition along the (002) plane. As a consequence, the NMXH─Zn//Zn cell exhibits an ultralow nucleation overpotential (1 mA cm−2, 18.9 mV) and can stably operate for 1400 h at 1 mA cm−2 (1 mAh cm−2) and 110 h at 40 mA cm−2 (1 mAh cm−2). A full battery with V2O5 nanowires as cathode displays a discharge capacity of 219 mAh g−1 (1.0 A g−1), along with a decent rate capability and cyclability. The significant role of N groups reported in this work offers a promising avenue to improve the cycling stability of Zn anodes of aqueous zinc batteries.