Enhanced performance of Li+ adsorption for H1.6Mn1.6O4 ion-sieves modified by Co doping and micro array morphology

The manganese based lithium ion sieve H1.6Mn1.6O4 is regarded as a promising adsorbent for recovering lithium from salt-lake brines. However, the poor recycle stability caused by the dissolution of manganese hinders its industrial application. In this work, the Co-doped H1.6CoxMn1.6-xO4 ion sieve with enhanced cycling performance for Li + adsorption was prepared through hydrothermal synthesis. The results of XRD and SEM indicated that Co-doping did not affect the spinel crystal structure of Li1.6Mn1.6O4 and a micro array structure was obtained. The cooperative effect of Co-doping and the micro array structure morphology on the Li + adsorption performance was investigated. Compared with H1.6Mn1.6O4(23.53 mg/g), the adsorption capacity of H1.6Co0.16Mn1.44O4 reached 29.95 mg/g. Also, H1.6Co0.16Mn1.44O4 showed excellent cycling performance that the Li + adsorption capacity maintained over 88% and the dissolution rate of manganese was below 2% after five cycles. The Co-doped H1.6CoxMn1.6-xO4 ion sieves show the prospects to be employed for the Li + extraction from aqueous lithium resources.