Abstract:
Nanocarbon conductive additives are important auxiliary materials for ensuring supercapacitors with high power. However, due to the insufficient ion transport channels, carbon black as the widely used conductive additive brings about poor rate capability for supercapacitors. Here, hollow carbon nanospheres(HSP) were prepared and applied as conductive additives for supercapacitors. HSP were obtained by a simple microwave-assisted high-temperature carbonization method with poly(aniline-co-pyrrole) copolymer hollow spheres as carbon precursors. The results showed that highly graphitized HSP not only had high electronic conductivity, but also retained electrolyte and provided more ion transport channels for more facilitating charge transfer of electrodes. As a result, the electrodes based on commercial activated carbons and HSP as conductive additives showed high specific capacitance from 108 to 98 F·g
-1 at current densities ranging from 1 to 10 A·g
-1, which was higher than that of conductive carbon black-based electrodes. Furthermore, HSP-based organic supercapacitors demonstrated high energy density(15.1 Wh·kg
-1) and high power density(10550 W·kg
-1), which were 130% and 40% higher than that of conductive carbon black-based supercapacitors(6.7 Wh·kg
-1, 7500 W·kg
-1), as well as maintaining excellent cycling performance. These findings indicate that the HSP used as hollow conductive additives could effectively improve the overall performance of supercapacitors.