The possibility of producing a biodegradable polymer electrolyte based on cellulose acetate (CA) with varied concentration of LiClO4 for use in supercapacitors has been investigated. The successful doping of the CA films has been analyzed by FTIR and DSC measurements of the LiClO4 doped CA films. The ionic conductivity of the films increased with increase in salt content and the maximum ionic conductivity obtained for the solid polymer electrolyte at room temperature was 4.9 x 10(3) ohm(-1) for CA with 16%, LiClO4. The biodegradation of the solid polymer electrolyte films have been tested by soil burial, degradation in activates Sludge, and degradation in buffer medium methods. The extent of biodegradation in the films has been measured by AC Impedance spectroscopy and weight loss calculations. The Study indicated sufficient biodegradability of the materials. A p/p polypyrrole supercapacitor has been fabricated and its electrochemical characteristics and performance have been studied. The supercapacitor showed a fairly good specific capacitance of 90 F g(-1) and a time constant of 1 s. (c) 2008 Wiley, Periodicals, Inc.