A novel composite of Co(OH)(2) and ultrastable Y molecular sieves was synthesized with an improved chemical precipitation method. The Co(OH)(2)/USY composite and its microstructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Co(OH)(2)/USY microstructure applied for the electrochemical energy storage displayed superior capacitive performance. Upon annealing at 100degreesC, the maximum specific capacitance was up to 958 F/g, which was comparable to that of hydrated ruthenium oxide. Higher annealing temperatures larger than 100degreesC only resulted in a decline of the specific capacitance. (C) 2004 Elsevier B.V. All rights reserved.