Towards low-temperature dendrite-free zinc anode by constructing functional MXene buffer layer with duplex zincophilic sites

Abstract

Dendrite growth and side reactions of zinc metal anode have severely limited the practical application of aqueous zinc ion batteries (AZIBs). Herein, we introduce an artificial buffer layer composed of functional MXene (Ti3CN) for zinc anodes. The synthesized Ti3CN exhibits superior conductivity and features duplex zincophilic sites (N and F). These characteristics facilitate the homogeneous deposition of Zn2+, accelerate the desolvation process of hydrated Zn2+, and reduce the nucleation overpotential. The Ti3CN-protected Zn anode demonstrates significantly enhanced reversibility compared to bare Zn anode during long-term cycling, achieving a cumulative plating capacity of 10,000 mAh cm−2 at 10 mA cm−2. In Ti3CN-Zn||Cu asymmetric cell, it maintains nearly 100 % Coulombic efficiency over 2500 cycles at 2 mA cm−2. Furthermore, the assembled Ti3CN-Zn//δ-K0.51V2O5 (KVO) full cell exhibit a low capacity decay rate of 0.002 % per cycle at 5 A/g. Even at 0 °C, the Ti3CN-Zn symmetric cell maintains steady cycling for 2000 h. This study introduces a novel approach for designing artificial solid electrolyte interlayers for commercial AZIBs.