Top-down Cutting Method for Construction of High-Performance Fiber-Shaped Quasi-Solid-State Asymmetric Supercapacitors

Fiber-shaped asymmetric supercapacitors (FSASCs) have great potential as a future wearable energy storage system because of good weavability, wide operating voltage window, and high energy density. Conventional bottom-up construction methods for fiber supercapacitors are time-consuming or highly costly. This work proposes a novel facile top-down cutting method to construct FSASCs. FSASCs with desired sizes can be rapidly constructed and easily scaled up by cutting a thin-film supercapacitor into fiber-shaped devices. Serial and parallel FSASCs free of external wire connection were assembled by cutting stacked film supercapacitors and multiplying the cutting width, respectively. Besides, the as-prepared FSASCs exhibit superior comprehensive electrochemical performance, including a high volumetric capacitance of 14.7 F cm-3, a high energy density of 93.5 μWh cm-2, and excellent flexibility. The cutting method with high simplicity, low cost, and high efficiency may be a general construction method for fiber-shaped energy storage devices.