3D network of zinc powder woven into fibre filaments for dendrite-free zinc battery anodes

Abstract

Zinc foil metal anodes in aqueous zinc ion batteries (AZIBs) are impaired by uncontrollable dendrite growth, resulting in low Coulombic efficiency (CE) and limited lifetime. The tunability of zinc powder provides a perfect alternative for anodes. But their rough spherical surfaces possibly make them more susceptible to corrosion and dendrite growth. We hereby utilise electrostatic spinning to weave zinc powder into polyacrylonitrile/ Polyvinylidene fluoride (PVDF/PAN) fiber filament to produce a new three-dimensional porous zinc anode (PF@Zn). Stable and flexible structure of the constructed fiber filament framework avoids direct contact of the aqueous electrolyte with the collector while relieving the stresses generated by dendrite growth. Moreover, when galvanizing or stripping, the zinc powder woven into the fiber network efficiently homogenizes the Zn2+ ion flux for a stable zinc cycle. Accordingly, the PF@Zn anode battery has a superior cycle life (240 h) and an increased Coulombic efficiency (99.1 %). An assembled C//PF@Zn capacitor has an impressive 96.6 % capacity retention after 3000 cycles. The study offers a scalable approach to modifying metal powder electrodes and transforming them into high-performance batteries.