<p>Aqueous fiber zinc-iodine batteries (FZIBs) with four-electron redox exhibit inherent safety and high energy density for wearable electronics. Nevertheless, their practical implementations are hindered by unsatisfactory cycling stability and low realistic energy density, which is mainly caused by the severe H₂O-induced nucleophilic attack toward iodine species and poor zinc anode reversibility. Herein, we report a quaternary ammonium-mediated coordination strategy to simultaneously address the irreversible cathode/anode redox behavior and thus promote the electrochemical performance of four-electron FZIBs. The cationic choline ion (Ch⁺) induces the complexation with ICl₂⁻ via the electrostatic interaction, which thus homogenizes the electron cloud density and suppresses the irreversible hydrolysis of I⁺ species, enabling a reversible near-theoretical high capacity of 418.3 mAh g⁻¹. Meanwhile, the preferentially adsorbed Ch⁺ on the zinc anode surface creates positively charged shielding layers, effectively mitigating the tip effect caused by the localized electric field and thus achieving the robust zinc stripping/plating process. The enhanced cathode/anode reversibility and the improved interfacial stability thus enable stable FZIBs operation for over 20,000 cycles under 20.0 A g⁻¹. Moreover, the successful integration of FZIBs into electronic textiles with glucose and cardiac rhythm sensors demonstrates great potential for next-generation wearable electronics.</p>