We are pleased to announce that research conducted by Nobuhiro Ogihara, Yuichi Itou, and Shigehiro Kawauchi of our company has honored with the Technical Development Award the Electrochemical Society of Japan (Tanahashi Award).

This award is presented to individuals who have achieved outstanding accomplishments in technological development based on electrochemistry and industrial physical chemistry.

We will continue to engage in a wide range of activities, from fundamental research to technology development leading to practical applications, thereby contributing to the realization of a sustainable society.

 

Award Recipients: Nobuhiro Ogihara, Yuichi Itou, Shigehiro Kawauchi
Award Theme: High-Precision Symmetric-Cell Impedance Analysis for Visualization of Resistance Components in Porous Electrodes

 

Abstract:

The performance of lithium-ion batteries is strongly influenced by the transport of electrons and ions within the electrodes, which governs the progression of electrochemical reactions. However, practical electrodes exhibit a complex porous structure characterized by finely distributed pores, making it difficult to accurately identify which resistance components limit performance.

In this study, we developed a novel impedance analysis method that combines symmetric cells—where electrodes in identical states are positioned opposite each other—with a mathematical framework known as the transmission line model. This approach enables the individual separation and quantitative evaluation of multiple internal resistance components within porous electrodes.

Using the proposed method, we clarified, through theoretical and experimental analyses, the mechanism linking power performance and electrode thickness and identified a correlation between low-temperature capacity retention and ionic resistance, providing insight into reaction non-uniformity within the battery. We also proposed a new mathematical model tailored to the complex porous structure and reaction non-uniformity. These findings offer practical design guidelines for achieving higher performance and longer lifetimes in next-generation lithium-ion batteries.

 

Related Papers:

  1. Ogihara, N., Kawauchi, S., Okuda, C., Itou, Y., Takeuchi Y., Ukyo, Y. “Theoretical and Experimental Analysis of Porous Electrodes for Lithium-Ion Batteries by Electrochemical Impedance Spectroscopy Using a Symmetric Cell.” Journal of The Electrochemical Society 159 (2012): A1034–A1039. https://doi.org/10.1149/2.057207jes
  2. Ogihara, N., Itou, Y., Sasaki, T., Takeuchi, Y. “Impedance Spectroscopy Characterization of Porous Electrodes under Different Electrode Thickness Using a Symmetric Cell for High-Performance Lithium-Ion Batteries.” The Journal of Physical Chemistry C 119 (2015): 4612–4619. https://doi.org/10.1021/jp512564f
  3. Ogihara, N., Itou, Y., Kawauchi, S. “Ion Transport in Porous Electrodes Obtained by Impedance Using a Symmetric Cell with Predictable Low-Temperature Battery Performance.” The Journal of Physical Chemistry Letters 10 (2019): 5013–5018. https://doi.org/10.1021/acs.jpclett.9b01670
  4. Itou, Y., Ogihara, N., Kawauchi, S. “Role of Conductive Carbon in Porous Li-Ion Battery Electrodes Revealed by Electrochemical Impedance Spectroscopy Using a Symmetric Cell.” The Journal of Physical Chemistry C 124 (2020): 5559–5564. https://doi.org/10.1021/acs.jpcc.9b11929
  5. Ogihara, N., Itou, Y. “Mathematical Model Based on Staircase Structure for Porous Electrode Impedance.” Physical Chemistry Chemical Physics 24 (2022): 21863–21871. https://doi.org/10.1039/D2CP02502G