Enhanced all-solid-state structural supercapacitor performance of rGO/N1C1M-S3’ nanosheets with high areal capacitance

All-solid-state structural supercapacitors (ASSCs), as a kind of multifunctional energy storage devices, show great application potential in the field of building. However, the inability to achieve high energy density is a major bottleneck in the application of ASSCs. Herein, a novel 3D nanosheet material is designed by a facile method, aiming to boost areal-energy-density for ASSCs. By doping of S (Na 2 S·9 H 2 O) on the rGO/N 1 C 1 M nanosheet (rGO/N 1 C 1 M-S 3 ’), we achieved an extremely areal capacitance of 9407.62 mF/cm 2 at 5 mA/cm 2 , which is much higher than 4421.33 mF/cm 2 (rGO/N 1 C 1 M). Definitely, this is the best performance reported so far for rGO/NCM electrode. An asymmetric ASSCs (1 cm × 1 cm×0.2 cm) prototype device exhibits excellent performance, with a high areal capacitance of 242.82 mF/cm 2 , a high areal-energy-density of 0.076 mWh/cm 2 at 3 mA/cm 2 . As a proof-concept-application. the ASSCs was enlarged to 4.5 cm × 4.5 cm × 0.2 cm, three ASSCs connected in series can light up a green light emitting diode indicator about ～1066 s, and can still work normally under the pressure of 500 g. The demonstration of employing rGO/N 1 C 1 M-S 3 ’ electrode opens up new opportunities to fabricate high performance ASSCs for structure energy storage in building.