Free-standing quaternized cellulose-based paper cathode enabling high-performance zinc-iodine batteries

Abstract

To address the issues of iodine dissolution and shuttle effect in zinciodine 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 markedly improves interfacial charge-transfer, accelerates the iodine redox kinetics, and enhances the binding of polyiodide ions through electrostatic interaction. 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.