Lithium battery electrodes incorporating nanoscale active components offer the potential for increased current and capacity over conventional electrode architectures, as the high specific interface inherent in such structures facilitates ion/electron transport. In our research, we seek to exploit the self-assembly of block copolymers in their use as an ion-conducting matrix and structure-directing agent for the fabrication of nanocomposite electrodes that incorporate nanoscale active components. Nanocomposite anodes have been prepared by in situ synthesis of lithium-alloying metals within a block copolymer electrolyte host. Nanocomposites for lithium battery cathodes were further obtained by sol-gel synthesis of vanadium oxide within a block copolymer electrolyte, employing an alkoxide precursor. Transmission electron microscopy studies of nanocomposite films reveal that V 2 O 5 forms a filamentous network confined within the ion-conducting domains of the block copolymer. Nanoscale confinement of the oxide yields films that are flexible and semi-transparent. Ongoing research addresses methods to incorporate sufficient electronic conduction to these nanocomposite cathodes for efficient battery operation.