Life expectancy and degradation behavior of electric double layer capacitor part I

General properties of various electric double layer capacitors (EDLC) have been introduced for power and industrial application. In this report, degradation behavior of the EDLCs was clarified. The capacitance decrease might be caused by the degradation of the electrolysis, propylene carbonate, and also the degradation by-products which piled on the nano-scale micro-cavity surface of the activated-carbon particles of the electrodes. The degradation mechanism was found to be governed by the Arrhenius chemical kinetics theory and consisted of two stages with different activation energy.