CHEMICAL LITHIUM INSERTION INTO SOL-GEL LAMELLAR MANGANESE-DIOXIDE MNO1.85-CENTER-DOT-NH(2)O

Chemical lithium insertion in the set-gel manganese oxide MnO1.85.nH(2)O has been performed using n-butyllithium as a reducing agent. Open-circuit voltage (OCV) experiments, IR, XRD and thermal analysis on lithiated samples LixMnO1.85.nH(2)O 0<x equal to or less than 0.45 show that lithium insertion into the host lattice induces a slight structural change: from x=0.05, a relative gliding of MnO6 layers occurs, leading to the transformation of the initial hexagonal structure into a closely related monoclinic phase. The higher the lithium content, the stronger the Li-hydrogen bond interactions which explains the contraction of the lattice observed along the c direction. The low magnitude of the structural changes is consistent with the high reversible behaviour found for this compound used as rechargeable cathodic material for lithium batteries.