High-reactivity electrode materials are indispensible for developing high-performance electrochemical energy storage devices. Herein, we report self-supported core/shell Co3O4/C nanowire arrays by using hydrothermal synthesis and chemical vapor deposition methods. A uniform and thin carbon shell is coated on the surface of Co3O4 nanowire forming core/shell nanowires with diameters of similar to 100 nm. Asymmetric supercapacitors have been assembled with the core/shell Co3O4/C nanowire arrays as the positive electrode and activated carbon (AC) as the negative electrode. The core/shell Co3O4/C nanowire arrays exhibit a specific capacity of 116 mAh g(-1) at the working current of similar to 100 mA (4 A g(-1)), and a long cycle life along with similar to 92% retention after 8000 cycles at 4 A g(-1), higher than the unmodified Co3O4 nanowire arrays (81 mAh g(-1) at 4 A g(-1)). The introduction of uniform carbon layer into the core/shell structure is favorable for the enhancement of supercapacitor due to the improved electrical conductivity and reaction kinetics. (C) 2014 Elsevier Ltd. All rights reserved.