Bottom-Up Fabrication of Sulfur-Doped Graphene Films Derived from Sulfur-Annulated Nanographene for Ultrahigh Volumetric Capacitance Micro-Supercapacitors

Heteroatom doping of nanocarbon films can efficiently boost the pseudocapacitance of micro-supercapacitors (MSCs); however, wafer-scale fabrication of sulfur-doped graphene films with a tailored thickness and homogeneous doping for MSCs remains a great challenge. Here we demonstrate the bottom-up fabrication of continuous, uniform, and ultrathin sulfur-doped graphene (SG) films, derived from the peripherical trisulfur-annulated hexa-peri-hexabenzocoronene (SHBC), for ultrahigh-rate MSCs (SG-MSCs) with landmark volumetric capacitance. The SG film was prepared by thermal annealing of the spray-coated SHBC-based film, with assistance of a thin Au protecting layer, at 800 °C for 30 min. SHBC with 12 phenylthio groups decorated at the periphery is critical as a precursor for the formation of the continuous and ultrathin SG film, with a uniform thickness of ∼10.0 nm. Notably, the as-produced all-solid-state planar SG-MSCs exhibited a highly stable pseudocapacitive behavior with a volumetric capacitance of ∼582 ...