Simultaneous Inhibitions of Volume Variation and Water Decomposition via Interwoven Structure of Hydrophilic/Hydrophobic Fibers for Stable Zn Electrode

Abstract Heterogeneous volume expansion and water decomposition‐induced zinc (Zn) corrosion are two of the main challenges hindering stable Zn electrodes in rechargeable aqueous Zn batteries (AZBs). Herein, an interwoven structure of hydrophilic/hydrophobic fibers is proposed to address the complex issue of Zn electrode, via a self‐assembly process of hydrophobic polyethylene terephthalate (PET) fibers and hydrophilic carboxylated carbon nanotubes (CNTs). It is revealed that O‐containing groups on the carboxylated CNT clusters can improve the Zn ²⁺ desolvation and transfer kinetics, thereby suppressing co‐decomposition of water molecules that are further excluded from the structure by the hydrophobic PET fibers, significantly suppressing hydrogen evolution reactions and Zn corrosions. Meanwhile, favorable formation of high‐work‐function Zn‐O sites on the O‐containing groups of carboxylated CNTs further engenders an electron‐withdrawing effect to enable in‐depth and confined Zn deposition, leading to a low volume variation of 13.8% for a practical Zn deposition capacity of 4 mAh cm ⁻² . Based on the simultaneous inhibitions of volume variation and water decomposition, high coulombic efficiency beyond 99.3% is realized for Zn plating/stripping at elevated current density up to 3 mA cm ⁻² , demonstrating the reliability of the interwoven structure of hydrophilic/hydrophobic fibers for stable Zn electrode in AZBs.