Hausmannite Mn3O4 polyhedral nanocrystals have been successfully synthesized via a simple solution-based thermolysis route using a three-dimensional hydrogen-bonded polymer as precursor. The as-obtained product was characterized by means of powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Possible formation mechanism of polyhedral nanocrystals was proposed based on the role of organic ligand dissociation from the polymer precursor at elevated temperature. The electrochemical capacitance performance of Mn3O4 electrode was investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. A maximum specific capacitance of 178 F g(-1) was obtained for the nanocrystals in a potential range from -0.1 to 0.8 V vs. SCE in a 0.5 M sodium sulfate solution at a current density of 0.2 A g(-1). (C) 2010 Elsevier B.V. All rights reserved.