Facile synthesis of nitrogen-doped hierarchical porous lamellar carbon for high-performance supercapacitors

Abstract

Three-dimensional (3D) interconnected N-enriched hierarchical porous lamellar carbon (NPLC) with a multilevel pore structure has been fabricated by a wet impregnation method using waste nitrogen-containing mantis shrimp shell as a carbon precursor and KOH as an impregnation solution. The synthesized NPLC-2 shows a large surface area of 1222.961 m² g⁻¹ calculated by the BET method, a hierarchical porous structure analyzed by the density functional theory (DFT) model, and a high nitrogen content of 1.78% quantified by X-ray photoelectron spectroscopy (XPS). Moreover, the NPLC-2 sample exhibits an ultra-high specific capacitance of 312.62 F g⁻¹ at 0.3 A g⁻¹, excellent rate capability with a specific capacitance of 272.56 F g⁻¹ at 20.0 A g⁻¹ and outstanding cycling stability with around 96.26% capacitance retention after 10 000 cycles at a high current density of 20.0 A g⁻¹. In addition, NPLC-2 presents a high energy density of 15.05 W h kg⁻¹ at 270 W kg⁻¹, and up to 10.12 W h kg⁻¹ even at a large power density of 14 580 W kg⁻¹. Therefore, the prepared material can be applied in high energy density and high power density demanding fields.