Study of lithium adsorption performance of Co doped manganese based lithium ion sieves prepared by solid phase synthesis

As global demand for lithium continues to rise, the extraction of lithium from lithium precipitation mother liquor has garnered significant attention. The manganese ion sieve (LMO) is a promising adsorbent, which can effectively adsorb lithium from complex solution. However, its inherent dissolution loss greatly restricts its practical application. In this study, introduced Co3+ doping to mitigate the manganese loss in LMO, resulting in the preparation of cobalt?doped manganese?based ion sieves (LCMO). LCMO prepared at various calcination temperatures and times were characterized using X?ray diffraction and scanning electron microscopy. The characterization results indicate that Co doping has no effect on the spinel structure of LMO, and Co doping amount of 5% can reduce the content of Mn3+ from 9.67% in the undoped precursor to 3.63%，significantly enhancing the lithium adsorption capacity to 41.7mg·g?1, greatly increasing the possibility of practical application. The 5% cobalt?doped ion sieve (HCMO?5%) has good cycling performance, and the adsorption capacity of Li+ remains above 81% after 5 cycles. In the simulated lithium precipitation mother liquor, the separation coefficient between Li/Na is 74.68, which proves that HCMO?5% can effectively adsorb Li+ from high sodium solutions. Therefore, HCMO?5% ion sieve has the application prospect of extracting Li+ from lithium water resources.