Gas bubble templated synthesis of Mn3O4-embedded hollow carbon nanospheres in ethanol flame for elastic supercapacitor

Abstract

With unique templates of sulphur-based gas bubbles in ethanol flame, the hollow carbon nanospheres, embedded with Mn3O4 quantum dots in the margin regions, are quickly synthesized on co-generated nanocarbon supporter on an elastic titanium foil substrate. The fabrication is just carried out by combustion in flame and anneal in air. When used as supercapacitor electrode, the electrode reveals large activity, high cyclic and elastic stability owing to its special structure. The mass specific capacitance of this nanosphere-based electrode is 316 F g−1 at a scan rate of 2 mV s−1, which is 94.7% larger than that of the electrode without nanosphere decoration. Furthermore, the capacitance retention of nanosphere-based electrode reaches 82.4% after 2000 charge-discharge cycles, and it is 78.3% even if the electrode is continuously vibrated 36000 cycles. These indicate the flame combustion method is effective, which has potential to be applied in synthesizing extensive materials in hollow nanosphere structure for electronic devices.