Effect of NaI/I2 mediators on properties of PEO/LiAlO2 based all-solid-state supercapacitors

By Yin, Yijing; Zhou, Juanjuan; Mansour, Azzam N. & Zhou, Xiangyang
Published in Journal of Power Sources NULL 2011

Abstract

NaI/I2 mediators and activated carbon were added into poly(ethylene oxide) (PEO)/lithium aluminate (LiAlO2) electrolyte to fabricate composite electrodes. All solid-state supercapacitors were fabricated using the as prepared composite electrodes and a Nafion 117 membrane as a separator. Cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge measurements were conducted to evaluate the electrochemical properties of the supercapacitors. With the addition of NaI/I2 mediators, the specific capacitance increased by 27 folds up to 150 F g-1. The specific capacitance increased with increases in the concentration of mediators in the electrodes. The addition of mediators also reduced the electrode resistance and rendered a higher electron transfer rate between mediator and mediator. The stability of the all-solid-state supercapacitor was tested over 2000 charge/discharge cycles.

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