Synthesis and Properties of Lithium Ion-sieve Precursor Li_4Mn_5O_(12)

Adsorption method is the most promising method for extraction of lithium from salt lakes.A new kind of MnO2 ion-sieves with high Li+ selective adsorption property were synthesized.Spinel-type Li4Mn5O12 precursors were synthesized by EDTA-citrate complexing method using LiNO3 and Mn(NO3)2.4H2O as starting materials.MnO2 ion-sieves with Li+ selective adsorption property were prepared by the acid treatment process to extract Li+ from the spinel Li4Mn5O12 precursors.As-prepared samples were characterized by thermo gravimetric,XRD,SEM,FT-IR and Li+ selective adsorption measurements,respectively.The results show that calcination time has a considerable effect on the structure and composition of precursors.The precursor calcined at 400℃ for 24 h has a pure phase of Li4Mn5O12.Final MnO2ion-sieve and Li4Mn5O12precursor are about 200 nm spherical pellets and have the same structure of spinel.The maximum adsorption capacity of ion-sieve is about 43.1 mg/g and has the good selection for Li+.