Densely packed hollow structured carbon with graphene-like shells on carbon cloth for high power supercapacitors

Supercapacitors are effective energy storage devices for electronics, with a prominent characteristics of high power density. Electrode design is an essential topic in the research of supercapacitors. In this study, we demonstrate a new type of supercapacitor electrodes and their fast charging/discharging application potential. Specifically, (1) Co-based compound nanowire arrays were first grown onto the carbon cloth by a facile hydrothermal route. (2) A chemical vapor deposition (CVD) process was subsequently performed, involving the in-situ thermal transformation of Co-based compound nanowire arrays to densely packed metallic sub-micron Co particles, and the following metallic cobalt catalyzed growth of nano-carbons onto the Co particles. (3) An acid etching process was finally carried out to remove the Co particles, leading to the formation of hollow structured carbon electrode materials on carbon cloth substrate. High magnification scanning electron microscopy (SEM) and element mapping technologies revealed the clear graphene-like carbon shells, and the intriguing hollow structure. Benefiting from the porous framework of carbon cloth for favorable accommodation of electrode materials, and the new type CVD produced hollow structured carbon particles with graphene-like shells for superior electronic and ionic conductivity, the electrode performance in three-electrode measurement indicates an successful electrode design.