Multifunctional structural composite fibers in energy storage by extrusion-based manufacturing

Flexible electronics have become increasingly important with growing market demands. Fiber-shaped supercapacitors and batteries are promising options for developing commercial applications due to their high power density, energy density, and mechanical properties. The bottlenecks of developing fiber-shaped supercapacitors and batteries include the inherent high resistance of electrode materials, low-yield manufacturing processes, and robustness of the fiber-shaped devices. Numerous studies on electrode materials, fiber structures, and manufacturing processes promote the electrical conductivity, surface area, and flexibility for high-performance fiber-shaped energy storage devices by extrusion-based manufacturing. This review provides an overview of the state-of-the-art of fiber-shaped supercapacitors and batteries including the electrode materials, fiber structures, and the extrusion-based manufacturing processes and highlight the research trend in the emerging field. The novel designs and manufacturing methods for fiber-shaped supercapacitors and batteries are also discussed to broaden the perspective in the emerging field.