In a cathode, the metal mesh serves as a current collector. The mesh is coated with a thin film comprising a mixture of an active cathode material and a carbon powder. The composition of the mixture and the processing thereof are optimized to obtain high electrochemical capacity, electrical conductivity, rechargeability, and mechanical integrity. LiCoO2 and LiFePO4 are active cathode materials that have been evaluated thus far. The chosen carbon powder is acetylene black, which is highly electrically conductive and is used to optimize the electronic conductivity of the cathode coating film.

For a given battery, electric power and mechanical strength can be increased by using a more processable electrolyte resin that performs well as a thin film. Reducing the thickness of the electrolyte increases the current by increasing the rate of conduction of ions between electrodes. In addition, the ability to fabricate a structural polymeric composite battery using only a small quantity of polymer electrolyte as a binder would enable the incorporation of a relatively large volume fraction of structural electrode materials; as a result, such a battery could have both greater strength and higher charge/discharge capacity than would otherwise be achievable.

The polymer electrolytes being developed for use in structural polymeric composite batteries can be characterized as load-bearing ion-conductive resins and nanocomposites of those resins. The specific resins receiving the most attention have been polymerized vinyl ester derivatives of poly(ethylene glycol) (PEG). A broad selection of monomers has been complexed with lithium triflate and thermally cured as solvent-free polymers. The etheric oxygen groups of PEG are capable of dissociating and transporting donor salt ions in the absence of solvents, while mechanical strength is provided by crosslinked vinyl ester networks. By varying the proportions, molecular structures, and functionalities of the vinyl ester and PEG constituents, it has been possible to tailor structural and electrolytic properties over wide ranges.