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

Abstract

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.