Cost evaluation and sensitivity analysis of the alkaline zinc-iron flow battery system for large-scale energy storage applications

Abstract

Alkaline zinc-iron flow batteries attract great interest for remarkable energy density, high safety, environmentally benign. However, comprehensive cost evaluation and sensitivity analysis of this technology are still absent. In this work, a cost model for a 0.1 MW/0.8 MWh alkaline zinc-iron flow battery system is presented, and a capital cost under the U.S. Department of Energy's target cost of 150 $ per kWh is achieved. Besides, the effects of electrode geometry, operating conditions, and membrane types on the system cost are investigated. The results illustrate that a low flow rate and thin electrodes with high porosity contribute to low capital costs under low current densities. Furthermore, the porous polybenzimidazole (PBI) membrane is more cost-effective than Nafion 212 membrane. This work provides an integrated estimation for the zinc-iron flow battery system, demonstrating its tremendous potential for grid-level energy storage applications.