Abstract : This report is a reprint from the Proceedings of Society for the Advancement of Materiel and Process Engineering (SAMPE) 2007 Symposium and Exhibition held in Baltimore, MD, on 3-7 June 2007. Multifunctional structural composites are being developed to simultaneously bear mechanical loads and store electrochemical energy. These composite batteries can replace inert structural components and concurrently provide supplementary power for light load applications. Significant weight savings can be achieved by designing composite battery components, packaging, electrolyte, separator, and/or electrodes with built-in structural and energy efficiency. Prior efforts have focused only on utilizing structural packaging with traditional battery components. In this approach, novel electrolyte and electrode materials are being developed to optimize both electrochemical and mechanical proper properties. Solvent-free structural vinyl ester polymer electrolytes are being formulated to achieve necessary mechanical strength while enabling ion conductivity. Structural carbon anodes and cathode materials deposited on metal substrates are being developed as electrode components. Charge/discharge cycling is used to evaluate electrochemical capacity of the electrode materials, and tensile tests are used to evaluate their mechanical properties. Several different structural separator materials are being investigated as well. All of these components allow the use of moldable, scalable, and cost-effective composite processing techniques.