From Salar to Cells: Validating Brine‐Sourced <scp>Li</scp>₂<scp>CO</scp>₃ from Salar de Uyuni for Lithium‐Ion Battery Cell Manufacture

In this study, lithium carbonate (Li 2 CO 3 ) sourced from the Salar de Uyuni salt flat in Bolivia was used in the synthesis of cathode active material for Li‐ion batteries. X‐ray diffraction, atomic absorption spectrometry, and scanning electron microscopy analyses confirmed that the material had a high phase purity (99.59%, battery‐grade) and a suitable morphology for active material synthesis, comparable to a similar commercially obtained material. Li[Ni 1/3 Mn 1/3 Co 1/3 ]O 2 (NMC111) was synthesized as a model system using Li 2 CO 3 as the precursor and evaluated in full, large‐format pouch cells along with three‐electrode cells, using commercially relevant active material fractions and mass loadings for meaningful assessment of electrochemical performance. These cells exhibited capacities close to theoretical values and similar to that of commercially obtained NMC111, demonstrating the viability of the raw material. Operando X‐ray diffraction analysis of aged pouch cells revealed that capacity loss was due to depletion of lithium inventory, without any disruption to the long‐range cathode crystal structure or significant degradation in lithium kinetics. Postmortem analysis of the cycled electrodes further confirmed that transition metal dissolution and lithium trapping on the anode side were key contributors to the capacity fading observed in the pouch cells. This work demonstrates the potential of Salar de Uyuni's lithium resources for the production of cells relevant to practical applications.