An asymmetric conducting polymer/polyoxometalate (POM) supercapacitor was designed using polypyrrole/phosphomolybdic acid and poly (3,4-ethylenedioxythiophene)/phosphotungstic acid as electrode materials. Performance characteristics were measured by cyclic voltammetry and constant current discharge. Energy density and power density were increased by a factor of 3 and 50, respectively, over symmetric conducting polymer/POM systems. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3464802] All rights reserved.