Improvement of lithium adsorption capacity of porous cylinder-type lithium manganese oxide through introduction of additive

Spinel lithium manganese oxides (LMOs) have been widely used as an adsorbent for the recovery of lithium from aqueous solutions due to its high selectivity. Here, we manipulated the powders into a cylindrical shape using water glass as a binder together with the reactants (Li2CO3 and MnCO3). The cylinder-type LMO showed a rather limited maximum adsorption capacity of 15.06 mg g−1 compared with that of 27.62 mg g−1 with LMO powder. To overcome this drawback, the effect of (Na2CO3) additive on the maximum adsorption capacity of cylinder-type LMO was evaluated by varying the additive amounts from 2 to 10 wt%. The maximum adsorption capacity increased to 19.19 mg g−1 by adding 7 wt% Na2CO3 as an additive. The enhanced adsorption capacity was believed to be the result of increased surface area due to the additional internal channels and pores introduced during the acid treatment. This study clearly demonstrates that the adsorption properties of cylinder-type LMO can be improved by using additives while maintaining the structural stability even after the heat treatment, lithium extraction, and lithium adsorption.