Authors:	Liu, Zhaoyang
Title:	Graphene based electrode materials for printable, high power and photo-switchable micro-supercapacitors
Online publication date:	3-Jul-2017
Year of first publication:	2017
Language:	english
Abstract:	In this thesis, micro-supercapacitors (MSCs) based on graphene or graphene composite materials were fabricated to address their unique properties such as facile printable device, high power density, and multi-functional application. In the 2nd chapter, solution fabrication of large area and highly conductive graphene films was developed, by facile spray coating of graphene-conductive polymer hybrid ink. The obtained graphene films exhibited excellent mechanical properties, which enabled their application as bottom electrodes for ultrathin organic photodetector devices. In the 3rd chapter, direct printing of in-plane MSCs on flexible substrates was demonstrated, employing both an electrochemically exfoliated graphene ink and a hybrid ink with an electrochemically active conducting polymer. The as fabricated MSCs on paper substrates delivered a significant areal capacitance. By employing ultra-thin PET substrates, “ultra-flexible” MSC devices were also achieved with excellent flexibility. In the 4th chapter, in-plane structured planar MSCs based on mesoporous polyaniline patterned graphene were introduced. The strong synergistic effect from electron-double-layer-capacitive graphene and pseudocapacitive mesoporous-PANi leads to excellent MSC device performances. The fabricated micro devices delivered both significant volumetric capacitance and rate capabilities, which further lead to a high power density. This performance outperformed most of those reported graphene-based high power supercapacitors/MSCs results. In the 5th chapter, in-plane structured planar MSCs with photo-switchable behavior were demonstrated, the fabricated devices can be operated at ultrahigh rates. The areal capacitance of these MSC devices showed a reversible modulation up to 20%. THz spectroscopy suggests that the optically switchable capacitance during UV/Vis light treatments was enabled by the optically shifted charge equilibrium at the diarylethene/graphene interface. The achievement of such smart MSC device opens up exciting opportunities for future portable and wearable power supplies in diverse applications with non-contact modulation of the properties.
DDC:	540 Chemie 540 Chemistry and allied sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 09 Chemie, Pharmazie u. Geowissensch.
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-875
URN:	urn:nbn:de:hebis:77-diss-1000013958
Version:	Original work
Publication type:	Dissertation
License:	In Copyright
Information on rights of use:	https://rightsstatements.org/vocab/InC/1.0/
Extent:	IV, 147 Seiten
Appears in collections:	JGU-Publikationen