Co ion-modified Li1.6Mn1.6O4 with enhanced Li+ adsorption performance and cyclic stability

The manganese-based ion sieve H 1.6 Mn 1.6 O 4 shows significant advantages in lithium adsorption. Its prominent features include high adsorption capacity and low pollution characteristics of the preparation process. These combined advantages make this material important in the lithium extraction technology in salt lakes. However, problems such as high manganese dissolution loss rate, poor cyclic stability, and difficulty in powder recycling seriously restrict the industrialized application. In this paper, we propose to optimize the structure of spinel-type manganese lithium ion-sieves with a 2% Co 3+ doping strategy, which can effectively inhibit the lattice collapse triggered by Jahn–Teller aberration during the pickling cycle by replacing part of the Mn 3+ active sites with Co 3+ . After doping, the relative Mn 4+ content on the surface of the material increased from 58%–61% according to the XPS test, confirming that the introduction of Co 3+ facilitated the transition of Mn 3+ to the higher valence state Mn 4+ through the charge compensation effect. Reducing the disproportionation activity of Mn 3+ reduces the dissolution loss of Mn 2+ during the pickling process. The experimental results showed that the adsorption of doped HMCO-2 material increased from 28.8–34.9 mg/g. The adsorption capacity retention rate was 77% after five cycles, there was a high selective adsorption of Li + , and the manganese dissolving loss rate was decreased to 2.3%.