Laser ablated uniform deposition of bismuth oxide film as efficient anode for zinc based flow battery

Abstract

Zinc based redox flow batteries are the most proficient and attractive candidature for large scale energy storage applications. However, zinc dendritic formation and inhomogeneous deposition of zinc hamper the cyclability of zinc-based flow batteries. Herein, we have successfully decorated Bi2O3 on the felt by using the pulsed laser deposition (PLD) technique and tested it as a negative electrode in zinc bromine redox flow battery. The Bi2O3 felt provides more robust nucleation sites for zinc nuclei, lowers the potential of hydrogen evolution reaction, minimizes the surface diffusion of zinc, lowers zinc nucleation overpotential, and triggers homogenous zinc deposits. Compared to pristine (57.7 %), Bi2O3 felt exhibited an energy efficiency of 70.6 % at 100 mA cm−2. Interestingly, the morphological evolution of zinc deposits demonstrates that zinc deposition on the Bi2O3 felt is more homogeneous than pristine at an initial time (30 sec of charging at 20 mA cm−2). Moreover, Bi2O3 felt shows a stable long cycling performance over 200 cycles with minimized charge discharge overpotential and exhibited an avg. coulombic efficiency of 96.78 % which is superior than pristine. Thus, Bi2O3 felt is a prominent anode material for improving the electrochemical performance of zinc based redox flow batteries.