Development of a New Lithium Sorbent

With the rapid development of lithium ion battery industry, the markets demand for lithium resources are booming across the world. Therefore, the interest in extracting lithium from brines including sea water has been significantly increasing because the amount of lithium in sea water is as high as 2.6×10¹¹ tons.  In this research, lithium manganese oxides (LMO) with spinel structure have been developed for lithium recovery from sea water or salt lake brines because of their unique advantages: high lithium sorption selectivity, relative low cost and environmentally friendly process for lithium adsorption/desorption. In the past few decades, the Li⁺ recovery capabilities of various kinds of LMO such as LiMn₂O₄, Li₄Mn₅O₁₂, Li_1.6Mn_1.6O₄ have been evaluated. However, the Li⁺ adsorption amounts of these adsorbents were low and reached about 50% theoretical adsorption value. In addition, the regeneration performances of the sorbents were poor. In this study, the porous LMO with 3D nano structure were prepared by using polystyrene template method. The test results showed the sorbent has a high Li⁺ adsorption capacity (higher than 55 mg/g in simulated lithium-rich sea water), an excellent stability, and a high lithium sorption selectivity. Moreover, the electrochemical systems for lithium recovery from aqueous system of the sorbent were also proposed to improve the lithium extraction efficiency.