3-Dimensional Porous Carbon with High Nitrogen Content Obtained from Longan Shell and Its Excellent Performance for Aqueous and All-Solid-State Supercapacitors

Abstract

Three-dimensional porous carbon is considered as an ideal electrode material for supercapacitors (SCs) applications owing to its good conductivity, developed pore structure, and excellent connectivity. Herein, using longan shell as precursor, 3-dimensional porous carbon with abundant and interconnected pores and moderate heteroatoms were obtained via simple carbonization and potassium hydroxide (KOH) activation treatment. The electrochemical performances of obtained 3-dimensional porous carbon were investigated as electrode materials in symmetric SCs with aqueous and solid electrolytes. The optimized material that is named after longan shell 3-dimensional porous carbon 800 (LSPC800) possesses high porosity (1.644 cm3 g−1) and N content (1.14 at %). In the three-electrode measurement, the LSPC800 displays an excellent capacitance value of 359 F g−1. Besides, the LSPC800 also achieves splendid specific capacitance (254 F g−1) in the two electrode system, while the fabricated SC employing 1 M Li2SO4 as electrolyte acquires ultrahigh power density (15930.38 W kg−1). Most importantly, LSPC800 electrodes are further applied into the SC adopting the KOH/polyvinyl alcohol (PVA) gel electrolyte, which reaches up to an outstanding capacitance of 313 F g−1 at 0.5 A g−1. In addition, for the all-solid-state SC, its rate capability at 50 A g−1 is 72.73% and retention at the 10,000th run is 93.64%. Evidently, this work is of great significance to the simple fabrication of 3-dimensional porous carbon and further opens up a way of improving the value-added utilization of biomass materials, as well as proving that the biomass porous carbons have immense potential for high-performance SCs application.

One-Pot Synthesis of an FeS@GQDs Composite for Lithium Storage with Coal Tar Pitch as ″Natural GQDs″

“…Two representative peaks are detected at ∼1350 and ∼1600 cm −1 for both GQDs and FeS@GQDs, representing the defects of the carbon structure (D band) as well as in-plane stretching vibrations of sp 2 hybridization of carbon atoms (G band). 36,37 Upon comparison with the spectrum of pure FeS, it can be concluded that these two characteristic peaks are only derived from GQDs, which affirm the presence of GQDs in the FeS@GQDs composite. Besides, for FeS@GQDs, the specific value of the I D /I G is 0.88, indicating that the carbon from GQDs is highly graphitized.…”

A Simple Route to Produce Highly Efficient Porous Carbons Recycled from Tea Waste for High-Performance Symmetric Supercapacitor Electrodes

“…Activated carbons (ACs) have been used as a conventional material for EDLC electrodes because of their intrinsic characteristic properties, such as high specific surface area, developed pore structure, and suitable surface chemical state [ 14 , 15 , 16 ]. Over the past years, much attention has been focused on transforming natural waste to worth-added ACs, such as carton [ 17 ], longan shell [ 18 ], sesame husk [ 19 ], lemon peel [ 20 ], walnut shells [ 21 ], lignocellulose [ 22 ], and palm [ 23 ]. As a result of the previous studies, it was found that there is great significance and research value in discovering low-cost and high-performance electrode materials by utilizing biowaste.…”

N-Doped Carbon Nanosheets from Biomass for Ultra Long-Cycling and High Energy Density Symmetric Supercapacitors

“…were used to make porous carbonaceous materials. [16][17][18][19][20][21] These biomass precursors produce carbons with controlled microstructure replicated from their parent biomass sources. Meng et al has recently reported such facile method of preparing supercapacitor electrodes from waste cigarette butts, which showed a high capacitance retention up to 45.75% at high current 10 Ag −1 .…”