Intelligent supercapacitor fibers with self-healing, electrochromic, and shape-memory capabilities are attractive components for next-generation power systems and wearable electronic devices due to their demonstrated high power density, cyclic stability, flexibility, and ability to be woven into breathable, power textiles. The aim of these devices is to allow the user to better adapt to complex and harsh environments. However, developing intelligent functions for specific real-word applications, such as being dark-environment identifiable to provide operational convenience and security in nighttime applications, remains a challenge.

Currently, lighting and energy storage units can realize this capability in combination. However, they need extra input power sources, which are bulky and inflexible, and may block the advancement of intelligent next-generation power systems and prove inconvenient for the user.

Meng Liao and colleagues of Fudan University and Ningguo Long Sheng Flexible Energy Storage Materials Technology Co. Ltd., China, recently published research on the development of a novel family of multicolor fluorescent fiber electrodes and supercapacitors in Small.

The researchers introduced the lighting function by incorporating fluorescent dye particles into multi-walled carbon nanotube (MWCNT) sheets via a cospinning process, typically resulting in passive lighting fluorescence that doesn’t require any input power. Through this process, a diverse range of colors can be readily produced (i.e., red, orange, yellow, green, blue and purple fibers are prepared by incorporating the corresponding dye particles). Furthermore, the fibers are flexible and can be readily woven into power textiles.

In comparison to existing systems that combine electrochromic and energy storage units, the research provides a wider range of coloration and continuous energy storage for flexible energy storage systems. Furthermore, the integration of fluorescence into supercapacitors extends their applications to labels, signs and warnings for smart electronics used in the dark. The authors stated that this work, “provides a new platform for aesthetic and customized design of wearable energy harvesting and storage devices aimed at real-world applications.”