Electrochimica Acta, Vol.228, 483-493, 2017
Flexible all-solid-state high-performance supercapacitor based on electrochemically synthesized carbon quantum dots/polypyrrole composite electrode
Recently, carbon quantum dots (CQDs) as a new zero-dimensional carbon nanomaterial have become a focus in electrochemical energy storage. In this paper, flexible all-solid-state supercapacitors (ASSSs) were electrochemically synthesized by on-step co-deposition of appropriate amounts of pyrrole monomer and CQDs in aqueous solution. The different electrodeposition time plays an important role in controlling morphologies of stainless steel wire meshes (SSWM)-supported CQDs/PPy composite film. The morphologies and compositions of the obtained CQDs/PPy composite electrodes were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectrum and X-ray photoelectron spectroscopy (XPS). Furthermore, a novel flexible ASSS device was fabricated using CQDs/PPy composite as the electrode and separated by polyvinyl alcohol/LiCl gel electrolyte. Benefiting from superior electrochemical properties of CQDs and PPy, the as-prepared CQDs/PPy composite ASSSs exhibit outstanding electrochemical performance with the areal capacitance 315 mF cm(-2) (corresponding to specific capacitance of 308 Fg(-1)) at a current density of 0.2 mA cm(-2) and long cycle life with 85.7% capacitance retention after 2 000 cycles. (C) 2017 Elsevier Ltd. All rights reserved.