Co3O4 nanorods are prepared by a facile calcinations of the Co-composites, which is synthesized with the precursors of CoCl2, 1,3,5-Benzenetri carboxylic acid (H3BTC) and phenanthroline (PHEN). The Co-composites nonorods are about 1 urn long and 50 nm wide. After calcinations, the Co3O4 nanorods are composed of nanoparticles of 20-40 nm in queue and possesses a surface area of 23 m(2) g(-1) owning to the release of the organic molecules. The electrochemical properties are examined by cyclic voltammetry, electrochemical impedance spectroscopy and cyclic charge-discharge tests. The results show that the Co3O4 have the highest specific capacity of 262 F g(-1) at 5 mV s(-1) in the range of 0.2-0.7 V (vs. Ag/AgCl) and have a good cycle life with nearly no decrease after 500 cycles at 50 mV s(-1). The asymmetrical Co3O4//AC button cell is also tested by two-electrode system with a large potential testing window of 1.5 V and the results show the high energy density with a value of 42.81 Wh kg(-1) at the discharge current of 1.5 Ag-1. (C) 2015 Elsevier Ltd. All rights reserved.