Development of impedance measurement of lithium ion batteries electrode using terahertz chemical microscope

In recent years, with the spread of electric vehicles, improvement in the performance of lithium ion batteries has been required. Evaluation of the active material is important because the performance of the lithium ion battery is affected by the movement of lithium ions at the electrode active material-electrolyte interface. In this study, we fabricated a lithium ion battery with the sensing plate, which is a potential sensor, attached to the positive electrode, and evaluated lithium ion battery with a terahertz chemical microscope (TCM). As a result, we succeeded in measuring the potential distribution of the positive electrode during charging and discharging, and the local impedance.