Environmental impact analysis of potassium-ion batteries based on the life cycle assessment: A comparison with lithium iron phosphate batteries

Potassium-ion batteries are being considered as a potential alternative to lithium-ion batteries due to their environmental friendliness and lack of dependence on scarce materials. However, it is currently unknown how their environmental impacts compare to that of LiFePO4 batteries. This study establishes a comprehensive and transparent life cycle inventory of four different types of potassium-ion batteries and presents a prospective cradle-to-grave life cycle assessment of these batteries. Potassium-ion batteries are found to be promising from a comprehensive life cycle perspective, particularly for KFeSO4F batteries. In terms of battery manufacturing, the utilization of aluminum foil as an anode collector allows the human non-carcinogenic toxicity and mineral resource scarcity values of potassium-ion batteries (except for KVPO4F batteries) to be only 15% and 24% of those of LiFePO4 batteries. However, the relatively lower energy density of potassium-ion batteries results in a less favorable performance than LiFePO4 batteries in the global warming and fossil resource scarcity categories. Furthermore, the environmental impacts for potassium-ion batteries arising from electricity losses in the use phase account for a significant portion of the entire system, contributing on average 59%, 52% and 48% to the global warming, fossil resourcing scarcity, and terrestrial acidification categories, respectively. For both potassium-ion and LiFePO4 batteries, the recovery of certain materials makes the hydrometallurgical recycling process have a positive environmental effect. Sensitivity analyses highlight the pivotal role of enhanced energy density and cycle life in the prospective advancement of potassium-ion batteries. This work provides a theoretical basis for future potassium-ion battery research.