In this work, nickel cobalt oxides with controlled morphology are fabricated through a facile surfactant free hydrothermal method. When using urea as precipitant, mesoporous microsphere assembled by densely packed nano-needles is obtained. The molar ratio between nickel and cobalt (nNi:mCo) shows a significant influence on the fine nanostructure as well as the electrochemical capacitive behaviors of the products. When nNi:mCo equals to 1, the as-prepared nickel cobalt oxide exhibits maximum specific capacitance value of 696 F g(-1) at a current density of 1 Ag-1 with high mass loading of 6 mg cm(-2), and excellent cycling stability (similar to 100% retention upon 5000 charge/discharge cycles at 10 A g(-1)) are achieved. (C) 2015 Elsevier Ltd. All rights reserved.