Quasi-solid-state fiber-shaped aqueous energy storage devices: recent advances and prospects
The currently on-going surge in portable and wearable electronics and devices has caused an ever-increasing rise in the requirement for highly compact and yet flexible energy storage devices (ESDs), especially for those quasi-solid-state fiber-shaped ESDs which possess a 1D unique architecture with a tiny volume, remarkable flexibility, and miniaturization potential. In addition, although non-aqueous fiber-shaped ESDs show obviously higher/more-competitive energy densities than their aqueous counterparts, the latter will be more attractive for a wider spectrum of applications when the overall performance, safety, cycle life and even cost are taken into consideration. Herein, in a timely response to this exciting development, we look into the recent advances in quasi-solid-state fiber-shaped aqueous ESDs, by providing a comprehensive and critical overview of new design principles, key progress in both materials and devices, and system integrations. The remaining challenges/opportunities will then be discussed, aiming to highlight the direction and development of fiber-shaped ESDs in the coming few years.