Atmospheric-Pressure Plasma Jet Processed SnO2/CNT Nanocomposites for Supercapacitor Application

　　We demonsrate a supercapacitor made of nanoporous SnO2/CNT (carbon nanotube)　composites that are sintered by nitrogen atmospheric pressure plasma jets (APPJs). The sreen-printing technique is first used to print a paste that contains SnO2 and CNT nanoparticles, ethyl celluloses, terpinoel. A nitrogen APPJ is then used to sinter the printed paste. With the increasing of APPJ sintering time, the wettability of SnO2/CNT composites also increases (lower water contact angle). Two different APPJ operation configurations are used in this study: one is with the stage fixed; the other is with a stage being scanned (moving stage, in order to process a sample with larger area). With the stage fixed, the best achieved specific capacitance is 188.42 F/g with 120 s processing duration. On the other hand, with the scanning stage, the best achieved specifnic capacitance is 89.6 F/g with 1.5 mm/s scanning speed. The scanning speed influences the processing time at a designated spot on the sample, thereby resulting in various properties of sintered SnO2/CNT composites. APPJ can be operated at a regular atmospheric pressure without using vacuum chambers and pumps that are expensive and require routine maintenance. Therefore, this technology has become a cost-effective tool readily for industrical application.