Lithium(1+) and magnesium(2+) extraction and lithium(1+) insertion

Chem. Mater. 1993,5, 311-316

311

Li+ and Mg2+Extraction and Li+ Insertion Reactions with LiMg0.5Mn1.504 Spinel in the Aqueous Phase Qi Feng,* Yoshitaka Miyai, Hirofumi Kanoh, and Kenta Ooi* Government Industrial Research Institute, Shikoku, 2-3-3Hananomiya-cho, Takamatsu 761,Japan Received September 29,1992. Revised Manuscript Received December 21,1992 Spinel-type lithium magnesium manganese oxide LiMgo.5Mnl.504 was prepared by a coprecipitation/ thermal crystallization method. Li+ and Mg2+ in the spinel-type lithium magnesium manganese oxide could be extracted by an acid treatment. The Li+ and Mg2+ extraction reaction with LiMg0.5Mn1.504and the Li+ insertion reaction with the acid-treated oxide were investigated by chemical, X-ray, DTA-TG analyses, FT-IR spectroscopy, pH titration, and Kd measurement. The extraction and the insertion proceed topotactically by ion-exchangetype mechanisms. The acid-treated oxide showed a lithium ion sieve property from microamount to macroamount of metal ion loading. The selectivity sequence for alkali metal ions was Na < K < Rb, Cs