▎ 摘　　要

Graphene surface modification by heteroatom incorporation is an attractive strategy to construct flexible electrochemical capacitors. Herein, the steam-assistant heteroatoms of sulfur and phosphorus dual-doped graphene film (s-SPG) is fabricated via an ice-template and thermal-activation approach and they demonstrate an excellent pseudocapacitive behavior in flexible electrochemical capacitors. As probed by various microscopic and spectroscopic analysis, well-maintained porosity structure is formed during the freeze-drying and steam-activation treatment; the increased surface roughness is ascribed to heteroatoms doping by the formation of S- and P-containing functional groups as electrochemical active sites. A flexible device integrated by porous s-SPG film shows high pseudocapacitive behavior with high specific capacitance (169 Fig), rate capability (91.7%) and cyclic stability (92.5%). Even at the bend angle of 120 degrees, no obvious change of specific capacitance is found indicating a good flexibility of s-SPG devices; the current study shows that s-SPG is a very promising electrode to realize the practical applications of all solid flexible supercapacitors. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.