It is generally acknowledged that the activation method and component of the precursor are of great importance for making porous carbon. In this study, four plant materials belong to one genus were selected as optimized plant material to produce hierarchical porous carbon for supercapacitors, the influence of initial structure was discussed. All the produced porous carbons have large specific surface area (higher than 2342 m2 g−1), high microporosity (more than 57%), and high pore volume (larger than 1.32 cm3 g−1). All the samples show characteristic of electrical double layer capacitance, and the onion-based porous carbon obtain highest specific capacitance of 568 F g−1 at the current density of 0.1 A g−1. With the current density rising from 1 A g−1 to 50 A g−1, the specific capacitance only decreases for 20%. After 5000 cycles, all the samples show relatively high capacitance retention (up to 97%). Two-step acid pickling has washed most impurities and directly lead to small equivalent series resistance (lower than 0.2 Ω). The samples show high power density and energy density (71 W h kg−1@180 W kg−1, 210 kW kg−1@33 W h kg−1). This study open an avenue to create high-performance hierarchical porous carbon based on plant architecture.
Developing heteroatom-rich porous carbon (HPC) for electricity storage promotes the use of green sustainable energy. To efficiently prepare and optimize HPC, it is necessary to explore its formation/doping mechanism. Here, HPCs are prepared from nontoxic organic crystals, and quantum chemical calculations and ReaxFF MD simulations are performed. Effects of carbon chains and functional groups on HPCs are investigated. In micromorphology, the open-chain compound changes little and is etched into interconnected particles. The compounds containing ring chains change a lot and form 2D thin layers. The dimer forms 3D flower-like structures composed of thin layers. During doping, N in the amino group has a tendency to form pyrrolic-N, and N in the N-heterocycle has a tendency to form quaternary-N. L-lysine-derived HPC shows a large specific surface area (3353.99 m 2 g −1 ). For symmetric supercapacitor, it possesses high specific capacitance (439.11 F g −1 at 0.3 A g −1 and 265.57 F g −1 at 100 A g −1 ) and high cyclic stability (maintained 96.86% after 5000 cycles). For asymmetric supercapacitor, it shows more pseudocapacitance (accounted for 33.84% at 20 mV s −1 ) and higher specific capacitance (586.58 F g −1 at 0.3 A g −1 and 457.40 F g −1 at 100 A g −1 ). In gel electrolyte, its power density and energy density increase by 39.58% and 133.21%, respectively, with voltage rising from 1 V to 1.4 V. The results provide theoretical guidance and high-performance HPCs for clean energy storage/conversion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.