In this work, Mn3O4 nanosheets were prepared by partially reducing MnO2, and then wrapped by graphene to form the composites. Flexible binder-free electrodes based on graphene-Mn3O4 nanosheets and carbon cloth were prepared with the assistance of poles repel. As electrodes for supercapacitors, the flexible electrodes exhibited a specific capacitance of 502 F g(-1) in 1 M Na2SO4 at a current density of 1 A g(-1). When performed at 5A g(-1), 84% of the original specific capacitance (300 F g(-1)) can be retained after 1000 cycles. Simultaneously, the comparison experiment between the binder-free and binder-contained electrodes confirmed the larger specific capacitance, lower impedance, and better rate capability of the former one. The strategy developed in this work may open up a general approach of poor conductivity of metal oxide-based binder-free electrodes for high-performance energy-storage devices. (C) 2015 Elsevier Ltd. All rights reserved.