Waterproof and Tailorable Elastic Rechargeable Yarn Zinc Ion Batteries by a Cross-Linked Polyacrylamide Electrolyte

TLDR: A high-performance, waterproof, tailorable, and stretchable yarn zinc ion battery using double-helix yarn electrodes and a cross-linked polyacrylamide (PAM) electrolyte, which demonstrates superior knittability, good stretchability, and superior waterproof capability.

Abstract: Emerging research toward next-generation flexible and wearable electronics has stimulated the efforts to build highly wearable, durable, and deformable energy devices with excellent electrochemical performances. Here, we develop a high-performance, waterproof, tailorable, and stretchable yarn zinc ion battery (ZIB) using double-helix yarn electrodes and a cross-linked polyacrylamide (PAM) electrolyte. Due to the high ionic conductivity of the PAM electrolyte and helix structured electrodes, the yarn ZIB delivers a high specific capacity and volumetric energy density (302.1 mAh g–1 and 53.8 mWh cm–3, respectively) as well as excellent cycling stability (98.5% capacity retention after 500 cycles). More importantly, the quasi-solid-state yarn ZIB also demonstrates superior knittability, good stretchability (up to 300% strain), and superior waterproof capability (high capacity retention of 96.5% after 12 h underwater operation). In addition, the long yarn ZIB can be tailored into short ones, and each part sti...