Battery performance, lifetime and safety are highly dependent on temperature. With the recent high demand for power capabilities, heat management has become increasingly relevant.
Research Papers
Measurement Approaches for Thermal Impedance Spectroscopy of Li-ion Batteries
Two novel measurement methods for capturing the thermal behaviour of Li-ion cells in the frequency domain
Authors: Cedric Kirst, Juan Ramos Zayas, Jan Singer
Highlights
- Two new measurement approaches for Thermal Impedance Spectroscopy of Li-ion cells
- Reduction of the state of the art thermal measurement time by 62%
- Thermal models show a MAE below 0.3 K on a validation measurement in the time domain
This work introduces two novel measurement methods for capturing the thermal behaviour of Li-ion cells in the frequency domain. For the validation, we compare them to the state of the art measurement method, in which the battery is thermally stimulated by a set of discrete frequencies, each tested individually in a sequential manner.
All experiments are conducted with a cylindrical 18650 LFP-Graphite cell and lead to similar thermal impedance spectra. We validate a 0-D thermal model fitted to the respective measurement results with a thermal step response in the time domain. The results show, that all three models accurately represent the thermal behaviour of a Li-ion cell, with a mean absolute error below 0.3 K on the validation test. A spider-web diagram classifies and compares the given methods based on five values showing, that the state of art thermal measurement time can be reduced by 62% while also increasing the impedance measurement resolution by measuring multiple frequencies simultaneously.
Access the paper here.
Featured Resources · Webinar
Beyond Lithium: Introducing TWAICE's New Sodium-Ion Battery Model
Explore the fundamentals, growing demand, and advantages of sodium-ion battery technology, including TWAICE's battery model, its potential applications in ESS and EVs, and its environmental and economic benefits.
August 20, 10:00am (ET) | 4:00pm (CET)
Sign upRelated Resources
Insights from EPRI's BESS failure incident database
This report is intended to address the failure mode analysis gap by developing a classification system that is practical for both technical and non-technical stakeholders.
Non-destructive electrode potential and open-circuit voltage aging estimation for lithium-ion batteries
In this publication we extend a state-of-the-art electrode open circuit potential model for blend electrodes and inhomogeneous lithiation. We introduce a bi-level optimization algorithm to estimate the open parameters of the electrode model using measurements conducted on the full-cell level with state-of-the-art testing equipment.
Mechanistic cycle aging model for the open-circuit voltage curve of lithium-ion batteries
Cycling lithium-ion batteries causes capacity fade, but also changes the shape of the open-circuit voltage (OCV) curve, due to loss of active material (LAM) and loss of lithium inventory (LLI). To model this change, we recently proposed a novel empirical calendar aging model that is parameterized on component states of health (s) instead of capacity fade only.
About the Authors
Cedric Kirst
Cedric Kirst is a Battery Engineer at TWAICE Technologies GmbH, where he has worked since August 2018. He also serves as an Associate Researcher at the TUM Chair of Electrical Energy Storage Technology, a role he has held since March 2023.
Cedric’s professional journey includes a significant tenure as a Student Assistant at the Bundeswehr University Munich from January 2017 to October 2019. He also gained valuable industry experience during his internship at IBM Research Dublin, where he participated in the EnableS3 project funded by the European Union.
Cedric holds a Master of Science in Mechatronics, Robotics, and Automation Engineering from the Technical University of Munich, completed in 2020. He also earned his Bachelor of Science in Engineering from the same institution in 2018.
Connect on Linkedin
Prof. Jan Singer
Dr. Jan Singer is Engineering Manager at TWAICE, where his primary focus is working on laboratory measurements and battery models. Before he joined TWAICE in 2019, he was a Research Associate at the Chair for Electrical Energy Storage Systems, Institute for Photovoltaics, University of Stuttgart, Germany. During his Ph.D. studies under the supervision of Prof. Dr.-Ing. Kai Peter Birke, he focused on the detection of electrochemical effects induced by volume strains and the development of new non-destructive characterization methods for lithium-ion cells. He started his professional career in 2006 as mechatronic technician at Harman/Becker Automotive Systems. In 2012, he received his Bachelor’s degree from University of Applied Sciences Ulm and graduated with an M.Sc. from University of Stuttgart in 2015.
Connect on Linkedin