High-Power Graphene-Carbon Nanotube Hybrid Supercapacitors

The bulky structure of current power sources is hindering the widespread development of next-generation electronics. Here, we propose a graphene/single wall carbon nanotube (SWCNT) hybrid structure for the realization of high-performance supercapacitors. The devices are assembled by using 2cm(2) area hybrid graphene/SWCNT electrodes, designed by combining a scalable solution-processing method (e.g., liquid phase exfoliation of pristine graphite and de-bundling of SWCNTs) with dynamic spray-gun deposition, and an aqueous electrolyte (3m LiNO3). This architecture allows us to effectively balance the supercapacitors performance achieving remarkable electrode gravimetric capacitance and specific energy at 2mVs(-1) of 104Fg(-1), 20.8Whkg(-1), respectively, and a maximum specific power of 92.3kWkg(-1). Our results, based on industrially scalable materials production and deposition methods, represent a real breakthrough compared to state-of-the-art lab-scale devices.