The development of highly-efficient and low-cost heteroatom-doped porous carbon materials is vitally important for high-performance supercapacitors. Herein, waste phenolic resin-based insulation boards, which naturally contain N and O elements, were deliberately chosen as an absolute “zero”-cost green raw material for the preparation of heteroatom self-doped porous carbon. Through carbonization and activation steps, N/O self-doped porous carbon with a high surface area has been successfully prepared. The constructed symmetrical supercapacitor based on the best sample thermally activated at 600 °C had a specific capacitance of 262.2 F g−1 at 0.5 A g−1. Furthermore, the output energy density was 17.4 W h kg−1 at a power density of 500 W kg−1. Impressively, a significantly stable cycling duration with almost 100% capacitance retention and coulombic efficiency were retained after running 20 000 cycles. Moreover, it took 150 h to self-discharge to half of its maximum voltage. The prominent performance of the constructed symmetrical supercapacitor was attributed to the large specific surface area, hierarchical pore size distribution, and optimal doped heteroatoms in the carbon matrix. This work uncovers a promising strategy of converting waste construction materials into high-value electrode materials for green energy storage applications, such as supercapacitors.

Insulation board-derived N/O self-doped porous carbon as an electrode material for high-performance symmetric supercapacitors

A review on power management systems: An electronic tool to enable microbial fuel cells for powering range of electronic appliances

N/S-Dual doped MnO modified spore-based ellipsoidal porous carbons for supercapacitors


 Biomass porous carbon has received widespread attention due to its application as electrode material for supercapacitors and adsorbent for difficult-to-degrade organic dyes. In this paper, biomass porous carbon KGL is prepared using ginkgo leaves as the precursor and KOH as the activator. Capitalizing on the adsorption property of porous carbon, an azo dye Congo red (CR) is confined into the nanopores of KGL to fabricate the KGL/CR electrode. The result suggests that KGL has good adsorption performance for organic dye and KGL/CR has excellent capacitance performance. When the CR concentration is 500 mg L-1, the adsorption capacity of KGL is 495 mg g-1. KGL/CR-500 displays elevated specific capacitance of 393 F g-1 at 1 A g-1 and excellent rate performance (76.3% capacitance retention at 10 A g-1). The capacitance retention after 10000 cycles maintains 99%. The symmetric supercapacitor has power density of 699.8 W kg-1 at an energy density of 16.4 Wh kg-1 and can power a light emitting diodes (LED). Our work provides the information that one is the treatment of organic dye wastewater, the other is development of electrochemical energy-storage materials, and may be expanded to the resource-utilization of other versatile effluent containing the redox groups.

Enhanced Electrochemical Performance of Biomass Porous Carbon Adsorption Congo Red

Effects of physical and chemical activations on the performance of biochar applied in supercapacitors

Biomass carbon materials have been widely used as electrode materials for super-capacitors (SC) due to their economic, environmental, and sustainable characteristics. In this work, we proposed that the Sapindus Mukorossi Peel (SMP) was used as a precursor to prepare a Sapindus Mukorossi Peel-based activated carbon material (SMPC) through carbonization and KOH activation. The morphology and structure of SMPC were characterized by various test methods. Cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) were used to characterize its electrochemical performance. The results show that SMPC has suitable pore size distribution, a large number of heteroatom functional groups and excellent electrical conductivity. In addition, the amount of activator also has an important influence on the performance of SMPC. When the mass ratio of carbon material to KOH is 1:3, the prepared sample SMPC-3 has the largest specific surface area (SSA) was 1254.5 m2/g. Moreover, SMPC-3 also has excellent electrochemical properties, high specific capacitance (at 1 A/g, the specific capacitance can reach 314.5F/g), good cycle stability (at 5 A/g, cyclic charge and discharge 5000 times, the specific capacitance is only lost by 4.2%.), superior rate performance (when the current density is increased from 0.5 A/g to 10 A/g, the specific capacitance retention rate is 80.4%). Assembling SMPC-3 // SMPC-3 into a symmetrical SC shows higher energy density (at 0.1 A/g, the energy density is 6.68 Wh/Kg) and power density (at 5 A/g, the power density is 3250 W/Kg).

Shuya Wang

Papers

N, O self-doped hierarchical porous carbon materials for high-performance super-capacitors