Water footprint of battery-grade lithium production in the Salar de Atacama, Chile

The increasing demand for lithium, driven primarily by the electric transportation and renewable energy technologies, highlights the need to comprehensively assess the environmental implications of its production. Thus, a profound exploration of the water-related impacts caused by the life cycle of raw materials like lithium is necessary. In this context, we performed a cradle-to-gate water footprint of lithium extracted from the Salar de Atacama (SdA) operation in Chile for the production period of 2022 and 2023. Based on a Life Cycle Assessment (LCA) approach we evaluated the water inventories and explored the potential impacts of water vulnerability and scarcity by applying AWARE and WAVE + characterisation models. This resulted in a total potential impact of 442 m 3 and 5.5 m 3 world equivalents per ton of lithium product (87% lithium carbonate (Li 2 CO 3 ) and 13% lithium hydroxide (LiOH)) for AWARE and WAVE+, respectively. The AWARE results indicate that concentrated lithium brine production significantly dominates the water footprint of lithium battery-grade products, with 326 m³ world equivalents per ton. WAVE + results are consistent, attributing 3.81 m³ equiv. to brine production. In the final production stages, the Li₂CO₃ production is prominent, with AWARE and WAVE + values of 59.9 m³ and 1.01 m³ equiv. per ton, respectively, largely due to sodium carbonate consumption and electricity generation. However, it is noteworthy that the water scarcity and vulnerability impacts remain minimal for these final production phases, which is primarily attributable to the utilisation of desalinated water. In addition, we compared the production periods of 2020–2021 and 2022–2023 finding that all measured indicators improved in 2022–2023 in the range of 9%–42%. This suggests increased efficiency of the operations in the SdA, with higher brine recovery rates and lower energy usage in certain process steps. The insights gained from this research contribute to the understanding of brine-based lithium production practices, providing a basis for exploring further mitigation strategies aimed at reducing the environmental footprint, particularly in production stages with higher water impact.