Ultrathin CoMn2O4 nanosheets grown on nickel foam have been prepared via a facile hydrothermal route with post-annealing treatments, and further investigated as a binder-free electrode for supercapacitors. Benefiting from the directing growth in current collector, porous structure and enough spaces between the neighbors nanosheets, CoMn2O4 electrode show enhanced capacitance performance with a specific capacitance of 1529 and 670 F g(-1) at current densities of 2 and 50 Ag-1, respectively, with a good cycling ability (100% of the initial specific capacitance remains after 3000 cycles). These results show that CoMn2O4 nanosheets with the nickel foam substrate obtained from this cost-effective synthesis route would have great potential applications in supercapacitors. (C) 2015 Elsevier B.V. All rights reserved.