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.
This study reports a method for preparing oxygen-rich carbon nanofiber film (OCNF) as a high-performance anode material for zinc-ion capacitors through hydrothermal nitric acid oxidation of carbon nanofiber film (CNF). By optimizing the nitric acid oxidation duration, OCNF exhibited exceptional hydrophilicity, electrical conductivity, and an abundance of oxygen-containing functional groups, which significantly enhanced the electrochemical performance of zinc-ion capacitors. Notably, OCNF-6h samples demonstrated high initial charge-discharge capacity (155.48 mAh g −1 at 0.2 A g −1 ) and remarkable long-term stability (retention rate of 94.5 % after 5000 cycles), along with high energy density (109.16 Wh kg −1 at 140.49 W kg −1 ). Notably, flexible OCNF-based devices maintain performance under 180°bending, enabling durable wearable energy storage solutions. This work highlights that the nitric acid oxidation strategy promotes the storage and diffusion of Zn 2+ on carbon-based material surfaces, presenting a promising new material for energy storage and flexible energy storage devices.
危险品化学品经营许可证（带存储）