An ionically conducting block copolymer was used as a template for the synthesis and confinement of lithium manganese oxide nanoparticles. The block copolymer functions as a polyelectrolyte and as a composite anode in a lithium battery system. Impedance spectroscopy and galvanostatic testing, X-ray diffraction and transmission electron microscopy were used to characterize the anode and polyelectrolyte. Galvanostatic testing indicates 300 or more cycles were possible without appreciable capacity fade. (C) 2004 Elsevier B.V. All rights reserved.