Nanoporous activated carbon material having a high specific capacitance in EDLCs and controlled oxygen content, and methods for making such activated carbon material. Reduction of oxygen content is achieved by (a) curing a carbon precursor/additive mixture in an inert or reducing environment, and/or (b) refining (heating) activated carbon material after synthesis in an inert or reducing environment. The inert or reducing environment used for curing or refining is preferably substantially free of oxygen.