Manganese-based spinel adsorbents for lithium recovery from aqueous solutions by electrochemical technique

The manganese-based spinel adsorbent (HMO) refers to lithium-ion adsorbents derived from the spinel lithium manganese oxide (LMO). Two types of lithium ions extraction composite films composed of HMO (HMn 2 O 4 and H 1.6 Mn 1.6 O 4 ) are successfully prepared by the blade coating method. Based on the excellent Li + selectivity of HMO and the outstanding conductivity of conductive carbon black (C), HMO/C films are carried out to extract lithium by electrochemically switched ion exchange (ESIX) technique. HMO has a certain adsorption capacity for Li + when the Li + concentration is close to the actual brine, and the adsorption capacity of HMn 2 O 4 and H 1.6 Mn 1.6 O 4 is 24.56 mg/g and 34.40 mg/g, respectively. HMO showed good selectivity for Li + in multiple metal ions solution. The capacity of HMn 2 O 4 and H 1.6 Mn 1.6 O 4 keep 80% and 86% of the initial values after 5 cycles, respectively. The inherent different lithium occupied leads to the difference of electrical-adsorption abilities between HMn 2 O 4 and H 1.6 Mn 1.6 O 4 . H 1.6 Mn 1.6 O 4 has a broad application prospect in lithium extraction from salt lake brine due to its lower application voltage, large adsorption capacity and superior stability.