Evaluation of quantity of stored charge in electric double layer capacitor by pulsed electro acoustic method

In this research, the space charge distribution in electric double layer capacitor (EDLC) for energy storage has been examined by a pulsed electro-acoustic (PEA) method. However, the measurement result has a reflection wave component generated by reflection and penetration of the acoustic wave, because the EDLC with five layer structures consists of three kind of materials (aluminum, cellulose, and activated carbon). Then, it is calculated from the acoustic impedance and relative permittivity of the material of EDLC, and examined the influence of reflected wave components on signal voltage. In this research, charge density influenced by reflection wave component from signal voltage was investigated. As a result, the correlation between signal voltage and charge density was understood, and the influence on charge distribution was examined.