Coaxially spinning stretchable zinc-ion battery fiber with waterproof and scissorability

Wearable energy storage with super mechanic flexibility, stretchability and safety has been in pursuit for smart flexible textiles. Fiber batteries, though having their superiority in spinnability, knittability and adaptability for breathable textiles with comparison to planar batteries, were normally produced with complicated procedures. To simplify the production process, in this study we showed that stretchable and scissorable Zinc-ion battery fibers could be spun through a dual-core spinning head with double concentric sheathes, by combining a one-step coaxial wet-spinning process and an in-situ photo-polymerization process. The resultant fibers showed super stretchability up to 500% strain. The presence of outer protection layer also offered super abrasion resistance and endurability to water and stress. Besides the spinnability and knittability into fabric, the battery fibers also maintained their functionality even after being cut into short segments. Thus, this study may not only offer a platform of one-step coaxial wet spinning process to produce battery fibers, but also offer an endurable energy-storage solution applicable in various wearable devices.