Porous carbon spheres（PCS） derived from lignin have been prepared through a facile method and fabricated as electrodes for electric double-layer capacitors. Spherical shaped mixtures of lignosulfonate and crystalize...Porous carbon spheres（PCS） derived from lignin have been prepared through a facile method and fabricated as electrodes for electric double-layer capacitors. Spherical shaped mixtures of lignosulfonate and crystalized KOH are formed by spray drying of a solution of lignosulfonate and KOH. Activation by KOH is performed at high temperatures along with lignosulfonate carbonization. With an appropriate pore structure, the obtained PCS have a specific surface area of 1372.87 m^2 g^-1 and show a capacitance of 340 F g^-1 in 3 M KOH at a current density of 0.5 A g^-1. Moreover, a symmetric supercapacitor fabricated using the PCS as electrodes show a maximum capacitance of 68.5 F g^-1, and an energy density of 9.7 W h kg^-1 at a power density of 250 W kg^-1. The capacity retention is more than 94.5% after 5000 galvanostatic chargedischarge cycles. The excellent characteristics seem to be ascribed to the pore structures of PCS that have a large specific surface area and a low electrical resistance.展开更多
Composites of mesoporous carbon（CMK-3） and Co3 O4 nanosheets grown on nickel foam were successfully synthesized by a simple route. A bare Co3 O4 film was synthesized for comparison. With the addition of CMK-3, the C...Composites of mesoporous carbon（CMK-3） and Co3 O4 nanosheets grown on nickel foam were successfully synthesized by a simple route. A bare Co3 O4 film was synthesized for comparison. With the addition of CMK-3, the Co3 O4 nanoparticles self-organize and agglomerate into nanosheets, showing a significant influence by CMK-3 on the morphology. The CMK-3/Co3 O4 exhibits an optimal specific capacitance of 1131.3 Fg^（-1） in 3 mol L-1 KOH aqueous electrolyte at 0.5 Ag-1, and a retention ratio of 91% over3000 cycles, both being much higher than that achieved from the bare Co3 O4 film（727 Fg^（-1） of specific capacitance, and 82% capacitance retention ratio）, indicating that the CMK-3/Co3 O4 nanosheets are very promising as electrode materials for supercapacitor applications.展开更多
文摘Porous carbon spheres（PCS） derived from lignin have been prepared through a facile method and fabricated as electrodes for electric double-layer capacitors. Spherical shaped mixtures of lignosulfonate and crystalized KOH are formed by spray drying of a solution of lignosulfonate and KOH. Activation by KOH is performed at high temperatures along with lignosulfonate carbonization. With an appropriate pore structure, the obtained PCS have a specific surface area of 1372.87 m^2 g^-1 and show a capacitance of 340 F g^-1 in 3 M KOH at a current density of 0.5 A g^-1. Moreover, a symmetric supercapacitor fabricated using the PCS as electrodes show a maximum capacitance of 68.5 F g^-1, and an energy density of 9.7 W h kg^-1 at a power density of 250 W kg^-1. The capacity retention is more than 94.5% after 5000 galvanostatic chargedischarge cycles. The excellent characteristics seem to be ascribed to the pore structures of PCS that have a large specific surface area and a low electrical resistance.
基金jointly supported by Shanghai Eastern-scholar program
文摘Composites of mesoporous carbon（CMK-3） and Co3 O4 nanosheets grown on nickel foam were successfully synthesized by a simple route. A bare Co3 O4 film was synthesized for comparison. With the addition of CMK-3, the Co3 O4 nanoparticles self-organize and agglomerate into nanosheets, showing a significant influence by CMK-3 on the morphology. The CMK-3/Co3 O4 exhibits an optimal specific capacitance of 1131.3 Fg^（-1） in 3 mol L-1 KOH aqueous electrolyte at 0.5 Ag-1, and a retention ratio of 91% over3000 cycles, both being much higher than that achieved from the bare Co3 O4 film（727 Fg^（-1） of specific capacitance, and 82% capacitance retention ratio）, indicating that the CMK-3/Co3 O4 nanosheets are very promising as electrode materials for supercapacitor applications.
