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

Abstract

A facile method has been developed to prepare a freestanding binder-free nitrogen-doped delaminated-Ti3C2/reduced graphene oxide hybrid films for high-performance supercapacitor electrodes. This film exhibits a high specific capacitance of 247 F g−1 (∼445.2 F cm−3) at 1 A g−1 in 6 M 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 15.7 W h 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.