Freestanding nitrogen-doped d-Ti3C2/reduced graphene oxide hybrid films for high performance supercapacitors

A facile method has been developed to prepare a freestanding binder-free nitrogen-doped delaminatedTi(3)C(2)/reduced graphene oxide hybrid films for high-performance supercapacitor electrodes. This film exhibits a high specific capacitance of 247 F g(-1) (similar to 445.2 F cm(-3)) at 1 Ag-1 in 6M KOH, which is still well maintained after 10000 cycles at 10 A g(-1), demonstrating excellent long-term electrochemical stability. In addition, a flexible symmetric supercapacitor has been assembled with such films that delivers a maximum energy density of 15.7Wh kg(-1) (at 309.3 W kg(-1)) and a power density of 3738.7 W kg(-1) (at 11.1 W h kg(-1)) in PVA/H2SO4 gel. This impressive electrochemical performance can be attributed to the enhanced conductivity and high pseudocapacitance offered by the heteroatoms of nitrogen and the alleviated self-restacking of MXene layers by the introduction of reduced graphene oxide nanosheets. (C) 2019 Elsevier Ltd. All rights reserved.