Comparative life cycle assessment of two different battery technologies: lithium iron phosphate and sodium-sulfur

The generation, storage and use of electric energy is a relevant issue for the modern society that is dependent from this energy typology for its activities (e.g. heating, goods production). Batteries are key components for the storage of electric energy, to be used for a large set of domestic, industrial and transport applications. The paper investigates the environmental impacts of two different battery technologies used as accumulator in the context of a production plant: (i) the lithium iron phosphate (LiFePO4) battery, and (ii) the sodium-sulfur (NaS) battery. The analyses have been performed according to the Life Cycle Assessment methodology, by using the ReCiPe method at midpoint and endpoint levels to quantify the potential environmental impacts. Results highlight the principal impact of two different technologies, considering all environmental indicators. Results show that the LiFePO4 solution can be considered the most sustainable solution for the considered industrial application. However, the difference is very small, within 2% and strongly influenced by the energy needed to recharge the batteries during the use phase. Instead, if we consider the production of batteries, the NaS solution resulted the most sustainable solution with an impact in terms of the aggregated single score damage category of about a half in comparison with the LiFePO4 solution.