Jingjing Mu

High-performance supercapacitor based on multi-structural CuS@polypyrrole composites prepared by in situ oxidative polymerization

We have developed a supercapacitor electrode composed of CuS microspheres with polypyrrole (PPy) uniformly inserted into the sheet-like subunit structure and coated onto the CuS surface to enhance the pseudocapacitive performance. Novel sphere-like CuS particles with intertwined sheet-like subunit structure are fabricated by a solvothermal approach without any surfactant or template. A CuS@PPy composite electrode is prepared by in situ oxidation polymerization of pyrrole in the presence of the CuS suspension. The CuS@PPy composite (CuS content is 16.7 wt%) exhibits a high specific capacitance of 427 F g−1 (at 1 A g−1) and its capacitance can still retain 88% after 1000 cycles.

Low-cost and high energy density asymmetric supercapacitors based on polyaniline nanotubes and MoO3 nanobelts

Asymmetric supercapacitors (ASCs) with high energy density are assembled based on the pseudocapacitance of both electrodes, which use polyaniline (PANI) nanotubes as positive electrodes and MoO3 nanobelts as negative electrodes in a 1 M H2SO4 aqueous electrolyte. The assembled novel PANI//MoO3 ASC device with an extended operating voltage window of 2.0 V, in spite of the use of an aqueous electrolyte, exhibits excellent performance such as a high specific capacitance of 518 F g−1 at a current density of 0.5 A g−1, reaching an energy density as high as 71.9 W h kg−1 at a power density of 254 W kg−1 and good cycling stability.

Formation of Carbon Nanosheets via Simultaneous Activation and Catalytic Carbonization of Macroporous Anion-Exchange Resin for Supercapacitors Application

Two-dimensional mesoporous carbon nanosheets (CNSs) have been prepared via simultaneous activation and catalytic carbonization route using macroporous anion-exchange resin (AER) as carbon precursor and ZnCl2 and FeCl3 as activating agent and catalyst, respectively. The iron catalyst in the skeleton of the AER may lead to carburization to form a sheetlike structure during the carbonization process. The obtained CNSs have a large number of mesopores, a maximum specific surface area of 1764.9 m(2) g(-1), and large pore volume of 1.38 cm(3) g(-1). As an electrode material for supercapacitors application, the CNSs electrode possesses a large specific capacitance of 283 F g(-1) at 0.5 A g(-1) and excellent rate capability (64% retention ratio even at 50 A g(-1)) in 6 mol L(-1) KOH. Furthermore, CNSs symmetric supercapacitor exhibits specific energies of 17.2 W h kg(-1) at a power density of 224 W kg(-1) operated in the voltage range of 0-1.8 V in 0.5 mol L(-1) Na2SO4 aqueous electrolyte, and outstanding cyclability (retains about 96% initial capacitance after 5000 cycles).

One-step preparation of ultrathin nitrogen-doped carbon nanosheets with ultrahigh pore volume for high-performance supercapacitors

A facile one-step activation and nitrogen-doping combination method is developed for preparation of nitrogen-doped graphene-like carbon nanosheets (N-CNSs). The N-CNSs have abundant wrinkled structures and ultrahigh pore volume (3.19 cm3 g−1), and are used as high-performance electrode materials for supercapacitors.

A novel fabrication of nitrogen-containing carbon nanospheres with high rate capability as electrode materials for supercapacitors

Nitrogen-containing polyaniline-based carbon nanospheres (C-PANI) with diameters of about 200 nm are prepared through a direct carbonization method using polyaniline (PANI) nanospheres as carbon precursors at different temperatures. The PANI nanospheres are synthesized via in situ oxidation polymerization of aniline in the presence of sodium carboxymethyl cellulose as a polymerization template. The C-PANI with 6.69% nitrogen content obtained at 800 °C (C-PANI-800) can achieve a high capacitance of 359 F g−1 at the current density of 1 A g−1 in 6 M aqueous KOH electrolyte, meanwhile maintaining excellent rate capability (81% retention at 20 A g−1). Furthermore, a symmetric supercapacitor fabricated with C-PANI-800 electrodes exhibits an energy density of 17.5 W h kg−1 at a power density of 227 W kg−1 and superior cycle stability (only 4% loss after 5000 cycles), operating in the voltage range of 0–1.8 V in 0.5 mol L−1 Na2SO4 aqueous electrolyte.