TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: In the method, thermally reducing the sheet of graphene oxide is performed: by convective heat transfer, where thermal reduction is performed at 700-1200 degrees C; or by photo-thermal reduction via a flash having an energy level of at least 150 Ws. The method further comprises: cycling the sheet of graphene in a half cell to initiate intercalation and lithium metal plating; applying a voltage between the sheet of graphene and a lithium-containing counter-electrode; and applying a voltage between the sheet of graphene and a metal foil counter-electrode immersed in an electrolyte containing lithium salts. Preferred Components: The lithiated porous graphene network cathode has an energy density of at least 630 Wh/kg and a capacity of at least 850 mAh/g, and a working voltage of 0.75 V. In the lithiated porous graphene network cathode: the sheet of graphene has a mass loading of lithium of 0.1-5 mg/cm2; and graphene has at least 25% divacancy defects. The cathode comprises essentially of lithium metal and graphene, and the anode comprises essentially of graphene. In the all-carbon battery, the electrolyte is an aqueous electrolyte.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: In the system (S1), the substrate is configured to be removable from the bath following deposition of the graphene oxide. The system (S1) further comprises: many rollers configured to advance the substrate through the bath, where the substrate is in the form of a web provided on at least one of the rollers; a drying zone downstream of the bath and configured to dry the graphene oxide deposited on the substrate; and a reduction zone downstream of the bath and configured to reduce the graphene oxide to graphene. POLYMER - Preferred Components: In the system (S1), the substrate comprises a hydrophilic porous polymer.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The lithium or lithium-containing compound is n-butyllithium.