Measurement of internal charge distribution in electric double layer capacitor by PEA method

In this study, the electrolyte was injected to Electric Double Layer Capacitor (EDLC) after degas treatment in vacuum and directly in air respectively and the internal charge distribution in the EDLC was examined by Pulsed Electro Acoustic (PEA) method. It can be found that volume charge density in case of injection of electrolyte after degas treatment in vacuum is about seven times compared with that injected directly the electrolyte in air. It was thought that the sufficient electrolyte can be injected in polarized microporous electrode by degas in the vacuum and more electric charges can be saved. Moreover, the sound velocity in the material is examined. It has been understood that electrostatic capacity gradually increases with the rise of applied voltage. The electrostatic capacity was estimated by PEA method and the energy conversion method, respectively. The results from two methods are in good agreement.