Transparent supercapacitors of 2 nm ruthenium oxide nanoparticles decorated on a 3D nitrogen-doped graphene aerogel

Although ruthenium oxide nanoparticles (RuO2), graphene, and their composites have been widely used as supercapacitor electrode materials, transparent supercapacitors of these materials have been rarely investigated. In this work, we fabricated high-performance transparent solid-state supercapacitors of 2 nm RuO2 decorated on a 3D nitrogen-doped reduced graphene oxide aerogel (NGA) with 27–54% transparency. The as-fabricated symmetric supercapacitor of RuO2/NGA at a finely tuned mass loading of 16.3 μg cm−2 with a finely tuned transmittance of 34.1% at a wavelength of 550 nm exhibits a maximum areal energy of 0.074 μW h cm−2 and a maximum areal power of 64 μW cm−2. The cycling stability of the device can also be maintained at 100% over 2000 cycles. The high transparent supercapacitor in this work may practically be used in many advanced transparent electrical devices.