A Novel Layered Sedimentary Rocks Structure of the Oxygen-Enriched Carbon for Ultrahigh-Rate-Performance Supercapacitors

In this paper, gelatin as a natural biomass was selected to successfully prepare an oxygen-enriched carbon with layered sedimentary rocks structure, which exhibited ultrahigh-rate performance and excellent cycling stability as supercapacitors. The specific capacitance reached 272.6 F g–1 at 1 A g–1 and still retained 197.0 F g–1 even at 100 A g–1 (with high capacitance retention of 72.3%). The outstanding electrochemical performance resulted from the special layered structure with large surface area (827.8 m2 g–1) and high content of oxygen (16.215 wt %), which effectively realized the synergistic effects of the electrical double-layer capacitance and pseudocapacitance. Moreover, it delivered an energy density of 25.3 Wh kg–1 even with a high power density of 34.7 kW kg–1 and ultralong cycling stability (with no capacitance decay even over 10 000 cycles at 2 A g–1) in a symmetric supercapacitor, which are highly desirable for their practical application in energy storage devices and conversion.