Daikichi Mukoyama

New Analysis of Electrochemical Impedance Spectroscopy for Lithium-ion Batteries

ABSTRACT: First of all, we express our deepest sympathies for the passing of Professor Su-Moon Park. In thepresent paper, an electrochemical impedance spectroscopy (EIS), which Professor Su-Moon Parkalso used frequently for the investigation of electroconducting polymer, is introduced as a recentevaluation tool for a commercially available lithium-ion battery (LIB). The paper surveys how todesign equivalent circuits while explaining physical and chemical phenomena in the LIB and howto get more accurate impedance spectra with varying the measuring temperatures. Additionally, asquare current EIS (SC-EIS) technique, which we have suggested, is introduced for the larger LIBsystem as a promising technique for the future.Keywords: Electrochenmical impedance spectroscopy, Lithium-ion battery, Equivalent circuit Received December 16, 2013 : Accepted December 23, 2013 1. Introduction Today, the economic growth in China and Indialeads motorization in the countries. The motorizationaccelerates the crises of fossil fuel shortage and envi-ronmental destruction. Therefore, the widespread useof green vehicles in the future is a necessity. In addi-tion, renewable energies such as solar power and windpower, whose energy generation depends on weatherof the area, have been introduced to reduce CO