Effect of Transition Metal Ions on the Reactive Crystallization and Morphology of Lithium Carbonate

The increasing demand for lithium‐ion batteries has intensified the importance of lithium carbonate, whose crystallization behavior, morphology, and filtration characteristics are influenced by crystallization conditions and transition‐metal impurities, particularly Ni 2+ , Co 2+ , and Mn 2+ . In this study, the effects of these ions on the reactive crystallization of lithium carbonate were systematically investigated. Crystal morphology and phase composition were characterized using SEM, FESEM‐EDS, XRD, and FTIR, while zeta potential measurements were performed to evaluate surface charge, and TGA was used to assess thermal decomposition behavior. The results showed that the presence of Co 2+ promoted more compact, rounded crystals with smoother surfaces, whereas Ni 2+ induced elongated, thin, plate‐like structures with increased surface irregularity. Mn 2+ resulted in intermediate shapes. Zeta potential measurements revealed a significant increase in surface charge in the presence of metal ions, enhancing electrostatic repulsion and reducing particle aggregation. Filtration behavior was also significantly influenced by crystal morphology: crystals formed in pure media exhibited the highest specific cake resistance, whereas Co 2+ and Mn 2+ substantially improved filterability by producing more permeable filter cakes, while Ni 2+ showed a moderate effect. These findings highlight the critical role of transition‐metal impurities in regulating lithium carbonate crystallization, crystal properties, and filtration performance.