A free-standing quaternized cellulose-based paper cathode enabling high-performance zinc–iodine batteries

Abstract

To address the issues of iodine dissolution and shuttle effects in zinc–iodine batteries, a cathode design strategy based on functionalized natural cellulose is proposed. A free-standing composite cathode composed of quaternized cellulose fibers, carbon nanotubes, and iodine solution was fabricated. Quaternization modification markedly accelerates the iodine redox kinetics and enhances the binding of polyiodide ions through electrostatic interactions. As a result, the cathode delivers an initial capacity of 193.0 mAh g⁻¹ and retains 170.2 mAh g⁻¹ after 10 000 cycles with a high capacity retention of 88.2%. This work provides a new biomass-based material design strategy for high-performance and low-cost zinc–iodine batteries.