Flexible and Robust Sandwich-Structured S-Doped Reduced Graphene Oxide/Carbon Nanotubes/Polyaniline (S-rGO/CNTs/PANI) Composite Membranes: Excellent Candidate as Free-Standing Electrodes for High-Performance Supercapacitors

•S-rGO/CNTs/PANI membranes were designed as free-standing electrodes for supercapacitor.•The flexible and free-standing electrode possessed good tensile strength of.•6.53 MPa.•They showed the most excellent electrochemical property among the reported G/PANI ones.

Paper-like flexible electrode becomes one of the most important research objects in energy storage. In the present work, sandwich-structured S-doped reduced graphene oxide/carbon nanotubes/polyaniline (S-rGO/CNTs/PANI) composite membranes were designed as free-standing electrodes for high-performance supercapacitors, by electro-deposition of polyaniline (PANI) onto the flexible and robust sandwich-structured S-doped reduced graphene oxide/carbon nanotubes (S-rGO/CNTs) composite films as highly conductive supports, which were prepared through a mild hydrothermal reduction and doping reaction of graphene oxide (GO) nanosheets in presence of multi-walled carbon nanotubes (MW-CNTs), with Na2S as not only a sulfur precursor, but also a high-efficient reducing agent. The S-rGO/CNTs/PANI composite membrane electrode possessed high specific capacitance (812 F/g) in 1.0 M H2SO4 aqueous solution, with excellent rate capability and cycling stability for supercapacitors without the need of current collectors and binders, showing significant potential in flexible energy storage devices.

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