Fig. 2. (a) Schematic of the ‘‘one for two’’ fabrication process: a 2D Co₃O₄ nanosheet cathode and N-doped carbon nanosheet anode are obtained from the same Co-MOF precursor, (b) CV curves and (c) Ragone plot of a CC@Co₃O₄//CC@NC asymmetric supercapacitor with a PVA–KOH gel electrolyte (modified from ref. 34, copyright permission from the Royal Society of Chemistry); (d) schematic of the atomic-level structure engineering of Zn_xCo_1−xO for high-rate intercalation pseudocapacitance applications and (e and f) computational investigations of oxygen-ion diffusion and electrical conduction in Zn_xCo_1−xO (modified from ref. 47, copyright permission from the American Association for the Advancement of Science).