Nuvoton Technology Corporation Japan


Nuvoton Technology Corporation Japan


  • HOME
  • Press Release
  • 240412_EIS

Press Release

Advancing Next-Generation Battery Diagnostic Technology for a Decarbonized Society

Report on Joint Research Outcomes in Battery Diagnostic Technology with AIST

APRIL 12, 2024

Kyoto,Japan,APRIL 12,2024 - Nuvoton Technology Corporation Japan (NTCJ) has presented the results of the joint research with the National Institute of Advanced Industrial Science and Technology (AIST), Research Institute of Electrochemical Energy at the 91st Meeting of the Electrochemical Society. The research focuses on the fitting methods of equivalent circuit models for battery internal impedance and the estimation of State of Health (SOH) using impedance.

Lithium-ion batteries (LIBs), compared to other types of batteries, offer numerous advantages such as high energy density and superior cycle characteristics, and are utilized in various applications today, including electric vehicles, smartphones, and industrial robots. In particular, LIBs used in new electric vehicles generally have a warranty on battery life for a certain term or mileage as well as SOH, considering safety and performance.

On the other hand, used automotive LIBs may be repurposed for different applications, and various companies are advancing research in this area. NTCJ has conducted joint research with the AIST Group with the aim of establishing a life degradation assessment method utilizing electrochemical measurement data of degraded batteries, and we have announced the outcomes of this research.

Presentation Theme .1:

Parameter Fitting of Equivalent Circuit Model for Electrochemical Impedance considering Temperature Dependence [1]

The construction of equivalent circuit models from the measurement data obtained by the EIS method validated a judgment method based on temperature dependency for the model's validity. The equivalent circuit model fitting method presented in this research involves all model parameters being related to temperature, and by incorporating a correlation formula between temperature and impedance to improve the fitting accuracy.

Presentation Theme .2:

Identification of battery impedance with SOH correlation and research on chemical basis [2]

The impedance component extraction from the equivalent circuit model fitting of each battery confirmed the correlation between SOH decrease and impedance increase due to degradation. To investigate the causes of impedance increase, LIBs were disassembled, and the extracted electrodes were evaluated and analyzed.


[1] Presented at the 91st Meeting of The Electrochemical Society, S8-3 1 06

[2] Presented at the 91st Meeting of The Electrochemical Society, S8-3 1 07

Moving forward, we will continue to advance research and development for the improvement of battery control technology and contribute to the energy society.

Contact Us

Media contact

Corporate Strategy Office, Nuvoton Technology Corporation Japan

Technical contact

Marketing Department, Battery and Analog Solution Business Group, Nuvoton Technology Corporation Japan

About Nuvoton Technology Corporation Japan

Nuvoton Technology Corporation Japan (NTCJ) joined Nuvoton Group in 2020. As a dedicated global semiconductor manufacturer,NTCJ provides technology and various products cultivated over 60 years since its establishment, and solutions that optimally combine them.We value relationships with our customers and partners, and by providing added value that exceeds expectations, we are working as a global solution company that solves various issues in society, industry, and people's lives.

For more information, please visit

The names of organizations, companies, products, or services mentioned in this press release are registered trademarks or trademarks of their respective companies or organizations. The information provided is current as of the date of publication and is subject to change without prior notice. Please be aware of this.