Synthesis and electrochemical performance of hierarchical porous carbons with 3D open-cell structure based on nanosilica-embedded emulsion-templated polymerization

A novel synthesis of hierarchical porous carbons （HPCs）with 3D open-cell structure based on nanosilica- embedded emulsion-templated polymerization was reported. An oil-in-water emulsion containing SiO2 colloids was fabricated using liquid paraffin as an oil phase, resorcinol/formaldehyde and silica sol as an aqueous phase, and Span 80/Tween 80 as emulsifiers. HPCs with macropore cores, open meso/ macropore windows, and abundant micropores were synthesized by the polymerization and carbonization of the emulsion, followed by scaffold removal and further KOH activation. A typical HPCs sample as supercapacitor electrode shows the charge/discharge capability under large loading current density （30 A/g） coupling with a reasonable electrochemical capacitance in KOH electrolyte solution.

Partially graphitic micro- and mesoporous carbon microspheres for supercapacitors

Partially graphitic micro- and mesoporous carbon microspheres （GMMCMs） were synthesized using hydrotbermal emulsion polymerization followed by KOH activation and catalytic graphitization. The resulting GMMCMs show micro- and mesopores with a specific surface area of 1113 m2/g, regular spherical shape with diameters of 0.5-1.0 μm and a partially graphitic structure with a low internal resistance of 0.34 Ω. The graphitic carbons as electrode for supercapacitor exhibit a fast ion-transport and rapid charge-discharge feature, and a high-rate electrochemical performance. The typical GMMCM electrode shows a specific capacitance of 220 F/g at 1.0 A/g, and 185 F/g under a high current density of 20.0 A/g in a 6 mol/L KOH electrolyte.

Zinc tartrate oriented hydrothermal synthesis of microporous carbons for high performance supercapacitor electrodes

A novel zinc tartrate oriented hydrothermal synthesis of microporous carbons was reported. Zinc–organic complex obtained via a simple chelation reaction of zinc ions and tartaric acid is introduced into the networks of resorcinol/formaldehyde polymer under hydrothermal condition. After carbonization process, the resultant microporous carbons achieve high surface area（up to 1255 m^2/g） and large mean pore size（1.99 nm） which guarantee both high specific capacitance（225 F/g at 1.0 A/g） and fast charge/discharge operation（20 A/g） when used as a supercapacitor electrode. Besides, the carbon electrode shows good cycling stability, with 93% capacitance retention at 1.0 A/g after 1000 cycles. The welldesigned and high-performance microporous carbons provide important prospects for supercapacitor applications.