Highly Shear-Thickening Electrolyte with Impact Resistance for Flexible Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries (ZIBs) are desirable for large-scale energy storage due to their high energy density, cost-effectiveness, and eco-friendliness. However, the enhancement of their durability under impact remains a major challenge since traditional liquid electrolytes are prone to leakage when subjected to severe shocks or impacts. In this study, a novel shear-thickening electrolyte was reported by integrating starch with Zn(CF₃SO₃)₂ electrolyte. Under normal conditions, this electrolyte behaves like a conventional liquid electrolyte with excellent ionic conductivity, low viscosity, and high fluidity. While upon exposure to external force stimuli, the liquid electrolyte can change to a solid. Moreover, the starch molecules have strong interactions with Zn²⁺, promoting the epitaxial electroplating of Zn on the anode and effectively suppressing dendrite formation. The ZIBs fabricated based on this shear-thickening electrolyte possess good electrochemical performance and stability, with a capacity retention rate of 96.5% after 3000 cycles at 2 A g^–1. More interestingly, the assembled AlVO/CC-50%/Zn flexible battery demonstrates high capacity retention after bending at angles of up to 90°. This shear- thickening electrolyte prevents the battery from damage caused by external force, thereby significantly boosting the impact resistance and the flexible properties of ZIBs.