Enhancing the Li+ adsorption and anti-dissolution properties of Li1.6Mn1.6O4 with Fe, Co doped

As a manganese-based Li+ ion sieve, H1.6Mn1.6O4 has the highest theoretical adsorption capacity drive from Li1.6Mn1.6O4. However, its industrial application is limited by large dissolution of Mn in the pickling process. In this work, we improved the Li+ adsorption and anti-dissolution properties by doping Li1.6Mn1.6O4 with different transition metal ions (Fe3+, Co2+). The characterization results of the materials indicated that no new impurities were introduced during the doping process (XRD) and a few Mn3+ was exist in the doped Li1.6Mn1.6O4 (XPS). The adsorption results shown that the adsorption capacities are 35.3 mg/g and 35.4 mg/g after doping with Fe3+ and Co2+ individually. Compared with undoped adsorbent (32.3 mg/g), these adsorption capacities of doping adsorbents are increased (CLi+ = 12 mmol/L; pH 12 t = 48 h). In the same time, the dissolution of Mn was 3.95% and 4.42% (CHCl = 0.6 mmol/L t = 24 h), which are improved the structure stability compared to undoped adsorbents (5.43%). The anti-dissoultion property of Ni doped Li1.6Mn1.6O4 does not improved maybe due to the severe cell expansion.