A Natural Solvent‐Based Gel Electrolyte for Stable and Sustainable Zinc‐Ion Batteries

ABSTRACT Natural solvent‐based electrolytes are increasingly sought for zinc‐ion batteries (ZIBs) as they provide a sustainable and cost‐effective means to regulate water activity and electrode–electrolyte interfacial chemistry while retaining the intrinsic safety of aqueous systems. Herein, a sustainable electrolyte formulation utilizing a chia seed (CS)‐based hydrogel is reported as an effective approach to improve the electrochemical stability of ZIBs. Owing to its high content of hydroxyl‐rich polysaccharides and phenolic compounds, the chia seed‐derived gel electrolyte (CSGE) tailors the Zn 2+ solvation environment, decreases free‐water activity, and restrains parasitic hydrogen evolution as well as dendritic zinc growth. Benefiting from this regulated solvation environment, the CSGE achieved a remarkably high Zn 2+ transference number of 0.84. Consequently, Zn//Zn symmetric cells demonstrated outstanding electrochemical stability exceeding 4000 h at 1.0 mA cm −2 and 1.0 mAh cm −2 . Moreover, Zn//V 2 O 5 cells achieved a high discharge capacity of 337.8 mAh g −1 at 0.1 A g −1 and maintained reliable rate performance between 0.2 and 10 A g −1 . In addition, ex situ SEM and XRD analyses revealed homogeneous deposition of Zn with a preferred (002) orientation. These findings demonstrate that electrolytes derived from renewable resources provide a cost‐effective route for stable and sustainable ZIBs.