Dendrite-free zinc deposition enabled by MXene/nylon scaffold and polydopamine solid-electrolyte interphase for flexible zinc-ion batteries

Abstract

The rapid growth of wearable and portable electronic devices calls for energy storage devices with good flexibility, high energy density, and safety. Rechargeable aqueous Zn ion batteries (ZIBs) with the merits of environmental benignity, high safety, and low cost have arisen as promising energy storage candidates for wearable electronic systems. However, the unstable Zn anode interface and notorious Zn dendrite formation hinder the application of flexible ZIBs. Herein, a highly stable and flexible Zn anode is developed by taking advantage of highly conductive Ti3C2 MXene coated nylon fabric (MXNY) as a three-dimensional (3D) Zn deposition skeleton and polydopamine (PDA) as a solid electrolyte interface (SEI). The combination of MXNY and PDA SEI provides synergistic benefits such as a stabilized interface for homogenous and dendrite-free Zn deposition and improved corrosion resistance. As a result, a flexible and stable Zn anode with improved Coulombic efficiency of 99.6 % at a current density of 10 mA cm–2 for 1 mA h cm–2, and long cycling stability of more than 3000 h at a current density of 0.5 mA cm–2 for 0.5 mA h cm–2 can be achieved. When paired with a flexible cathode, the quasi-solid-state ZIB can power various electronic devices under different mechanical deformations, indicating its promising potential as flexible energy storage devices for wearable and portable electronics.