Lithium intercalation behavior of iron cyanometallates

Iron cyanometallates having a formula, M-6-m(n+)[Fem+(CN)(6)](n) (M = V, Mn , Co, Ni, Cu) were prepared and their charge-discharge behavior was discuss ed. In the V-Fe complex, average discharge potential is about 3.6 V corresp onding to reduction of V3+, whereas the Mn, Co, Ni, and Cu complexes show s imilar discharge potential around 3.3 V that is resulted from reduction of [Fe3+(CN)6](3-) unit in the lattice. The specific capacity of V, Mn, Co, Ni complexes show about 60-80 mA h g(-1), but copper complex indicates almost double capacity, ca. 140 mA h g(-1). This is explained by considering the capacity caused by Cu2+ to Cu+ reduction in addition to [Fe3+ (CN)(6)](3-) --> [Fe2+(CN)(6)](4-) reduction. (C) 1999 Elsevier Science S.A. All rights reserved.