Robust Aqueous Zn-Ion Fiber Battery Based on High-Strength Cellulose Yarns

Fiber batteries are easily integrated with textiles to power wearable electronics because of their one-dimensional shape. Fiber batteries should meet the requirements of excellent mechanical strength, flexibility, durability, and superior electrochemical performance. Herein, high-strength cellulose yarns, lightweight, low-cost, and sustainable, are adopted as robust and flexible substrates of both cathode (polyaniline) and anode (metal Zn) of an aqueous Zn-ion fiber battery. The fiber battery delivers an energy density of 153.2 and 61.1 Wh/kg at a power density of 0.16 and 6.5 kW/kg, respectively (based on the total active mass of the cathode and anode). Meanwhile, superior cyclic stability and high flexibility are exhibited by the fiber battery. The capacity retention is 91.9% and 97.5% after 1000 charge/discharge and bending cycles, respectively. Impressively, the fiber battery works well under a mechanical load of 100 g to power an LED indicator.