Overview of fiber-shaped energy storage devices: From fabrication to application

Given the rapid progress in flexible wearable electronics, fiber-shaped energy storage devices (FESDs) with the unique advantages of miniaturization, adaptability, and wearability are considered potential candidates. This review summarizes the research progress of FESDs in recent years, starting from device structures and fabrication strategies to performance evaluation. The pros and cons of each of the strategies and configurations are discussed. The development of FESDs, including fiber-shaped lithium-based batteries, fiber-shaped sodium-based batteries, fiber-shaped zinc-based batteries, and fiber-shaped supercapacitors, is comprehensively presented. In addition, the application scenarios of FESDs providing energy for smart textiles, wearable electronic devices, implanted medical devices, and flexible robots are introduced. Although significant progress has been made, there remain challenges to the commercialization of current FESDs, such as difficulties caused by small-sized and multi-component structures, unsatisfactory energy density and cycle life, and obstacles to integration and large-scale applications. Finally, the future research directions and prospective opportunities in the field are provided.