▎ 摘　　要

Herein, sulfur-doped graphite film (SGF) is developed by a facile method. Graphene oxide (GO) film and low-cost NaHSO3 are used for carbon and sulfur sources, respectively. A single-step sulfur doping reaction is used to obtain SGF at 180 degrees C. The scanning electron microscopy (SEM) analysis of SGF reveals highly loose, highly crumpled characteristics. The SEM-energy-dispersive spectroscopy shows that S is evenly distributed on the surface of SGF and doping amount of S is 4.6 wt%. SGF can attain high gravimetric and areal specific capacitance of 232.8 F g(-1) and 672.5 mF cm(-2) at 0.5 A g(-1) and 1 mA cm(-2) current density, respectively. The SGF shows excellent cycle stability (94.1% capacity retention after 10 000 cycles at 2.0 mA cm(-2)). Then, the assembled flexible SGF//SGF all-solid-state symmetric supercapacitor device can deliver a high energy density of 12.17 Wh kg(-1) at a power density of 499.85 kW kg(-1). The in situ doping method provides a simplistic and low-cost synthesis process, which is suitable for large-scale production of SGF. Furthermore, the well-developed approach is applied to prepare arbitrary S-doped matrix of carbon. Simultaneously, the fabricated SGF as the electrode material of flexible supercapacitor devices has great advantages in wearable electronics.