Fiber-Shaped Energy-Storage Devices

With the rapid development of science and technology, portable and wearable electronic devices presented a prominent technological trend for future lifestyles and they have brought enormous convenience to our daily life. In order to realize the wearability of the whole equipment, it is necessary to develop matching high flexible, lightweight and small volume energy supply devices. The volume of planar flexible energy-storage device is too large to be integrated into the fabric, so it is difficult to give full play to the advantages of energy storage device. The fiber-shaped energy storage devices with their unique advantages of tiny volume, high flexibility and remarkable wearability have triggered wide attention. Thus, developing high-performance fiber-shaped energy storage devices is recognized as a promising strategy to address the above issues. This chapter discusses the design principles and device performance of fiber-shaped energy storage devices. In the first section, design principles of fiber-shaped energy storage devices with fiber electrode, electrolyte and device configurations are presented. In the next section, the development of fiber-shaped energy storage devices, including supercapacitors, nonaqueous and aqueous batteries, are comprehensively summarized, with particular emphasis on electrochemical and mechanical properties. The existing challenges and future directions are finally discussed to provide some useful insights from the viewpoint of practical applications.