Construction and Characterization of a Reference Spectrometer for Calibration of Reference Impedances in mOhm Range

Application Deadline: 
Tuesday, February 28, 2017

The Braunschweig International Graduate School of Metrology together with the Technical Cooperation of PTB offer the opportunity for currently two PhD scholarships each year for students engaged in natural sciences or engineering. The funding is provided by the German Federal Ministry for Economic Cooperation and Development (BMZ) to support developing and emerging countries (please see full list of partner countries) in the field of quality infrastructure. Initially, funding will be granted for one year. Given that it typically takes three years to complete a doctoral thesis PTB will be committed to obtain a follow-up funding. The size of the grants is comparable to grants provided by the German Academic Exchange Service (DAAD). The scholarships will be located at TU Braunschweig.

An excellent academic record and fluent English are prerequisites; skills in the German language are welcome. The submission should include CV, transcripts of the most important documents of professional qualification and a letter of application. B-IGSM promotes the professional equality of women and men and is thus especially interested in applications from women. Disabled persons will be given priority if they have the same occupational aptitude. Any granting of a scholarship has to be approved by the International Office of TU Braunschweig taking into account the Promotionsordnung (PhD Regulations) of the respective faculty where the scholarship will be located.

Please note that any application needs to be submitted via the application portal of B-IGSM.

Construction and Characterization of a Reference Spectrometer for Calibration of Reference Impedances in mOhm Range

Impedance spectrometers are now increasingly used for the metrological characterization of High energy Li-ion batteries. Battery storage systems are important parts for electric mobility and Energiewende. The electrochemical working group of PTB has developed a reference measurement setup to derive empirical parameters from electrochemical impedance spectra of Li-ion battery cells that are sensitive to aging of Li-ion battery cells. The Institute for High Voltage and Electrical Power Systems of the TU Braunschweig examines at the Battery LabFactory Braunschweig (BLB) the influence of formation on cell performance and develops analytical methods for determination of quality indicators. To derive the cell performance, the cell is aged cyclic and calendrically at different conditions while the SOH (State of Health) is continuously monitored. At PTB the SOH is determined according to a specially developed method of electrochemical impedance spectra. As part of the PhD project the PHD student at PTB builds a measuring station. This station should be able to measure AC current, AC voltage and their respective phase position independently at impedances in the mΩ range. The spectrometer has to be characterized in terms of stability, repeatability and measurement error. This measuring station also has to be able to be used as a calibration reference for impedances, which in turn are used for calibrating impedance spectrometers. The spectrometer is intended to enable the return of the measured impedance spectra, for SOH determination, to the International System of Units.

Applicants should have a master or comparable degree in physics, chemistry or engineering and basic experience in power electronics.

Further information:
Prof. Dr. Michael Kurrat
Institute for High Voltage and Electrical Power Systems
TU Braunschweig
m [dot] kurrat [at] tu-braunschweig [dot] de

TU Braunschweig