Continuous wet spinning of V2O5 fiber electrodes with silver-plated yarn core for Zn ion fiber batteries.

Structural energy storage technology is a potential solution to reduce the weight of electrical energy storage systems. Zn ion fiber batteries are important for this technology given their flexibility, safety, and lightweight. As a component of fiber battery production, the structural design of fiber electrodes is caught in a dilemma. Fiber electrodes with core are difficult to prepare continuously, while fiber electrodes without core have unsatisfactory mechanical strength. Herein, a wet spinning method is used to prepare fiber electrodes with core continuously at a speed of 25 mm s−1. Raw commercial vanadium pentoxide powders, acetylene black, and polyvinylidene fluoride are mixed into a slurry. A special tapered concave nozzle is designed to make the slurry saturate the core fully and be extruded well. Therefore, the fiber electrodes own a high ultimate tensile strength of 303 MPa and maintain the microstructure after 5000 bending cycles. The Zn ion fiber batteries exhibit a specific capacity of 134 mAh g−1 at 0.1 A g−1 after 100 cycles. This work shows a simple and efficient way to prepare fiber electrodes with core, which provides a new strategy for flexible electronic manufacturing and structural energy storage technology. [Display omitted] • Vanadium pentoxide coated on the silver-plated yarn is used in the Zn ion batteries. • A wet spinning method is designed to prepare fiber electrodes simply. • A unique tapered and concave nozzle is used to improve the extrusion process. • Fiber electrodes with core exhibit a good tensile strength and electrical performance. • Finite element simulation is used to investigate the fluid in the extrusion process. [ABSTRACT FROM AUTHOR]