Environmental and Preliminary Cost Assessments of Redox Flow Batteries for Renewable Energy Storage

The sustainable use of energy is one of the main challenges currently. The increase in the use of renewable energies must also be accompanied by storage systems that respect the environment or are as harmless as possible. In this work, life-cycle assessment (LCA) from cradle to gate and a preliminary cost assessment of two types of redox flow batteries, such as vanadium redox flow batteries (VRFBs) and zinc/cerium batteries (ZCBs), are studied. Ecoinvent 3.3 data base, AWARE, and CML Baseline v3.04 methodologies are used to quantify the environmental burden into 12 midpoint impact categories (water footprint, global warming 100a, abiotic depletion, abiotic depletion [fossil fuel], ozone layer depletion, human toxicity, fresh water ecotoxicity, terrestrial ecotoxicity, marine ecotoxicity, photochemical oxidation, acidification, and eutrophication). All impact categories are higher in ZCBs than in VRFBs except water footprint and acidification. These midpoint impacts are also compared with conventional batteries (lithium) and nonconventional ones (NaNiCl). VRFBs have the lowest environmental impact and a longer life considering the reuse of vanadium electrolytes. Regarding the cost analysis, the electrolyte is the most expensive component of both batteries.