Master thesis: Modeling of equivalent circuits to describe elementary processes in SOFC / SOEC

Forschungszentrum Jülich - FZJ - Helmholtz Association

Jülich, Germany

Work group:

IEK-9 - Grundlagen der Elektrochemie

Area of research:

Diploma & Master Thesis

Starting date:


Contract time limit:


Job description:

The group “Electrochemistry” of the institute Fundamental Electrochemistry (IEK-9) at Forschungszentrum Jülich is currently looking for a Master thesis candidate who possesses the below listed qualification for the earliest possible employment date.

Your task:In the framework of several national and international projects the group investigates electrochemical processes in solid-oxide fuel cell (SOFC) and solid-oxide electrolysis cell (SOEC). Electrochemical Impedance Spectroscopy (EIS) is a powerful tool used to characterize complete cells and anode and/or cathode half-cells. Using this tool a small alternating electrical impulse (voltage/current) is applied to the cell, and the response of the cell (current/voltage) is recorded. The obtained impedance spectra are usually analyzed with and fitted to equivalent circuit models (ECM). An ECM consists of electrical elements, like resistors, inductances and capacitors, connected in series and/or parallel. These elements describe physical-chemical processes occurring at/in the electrode/electrolyte interfaces in the cell.

The main question in the analyses of impedance spectra always is which combination of these electrical elements the complex system completely describes. Helpful in this is the analysis of the distribution of relaxation times (DRT) of the impedance data, a method that characterizes the response in rates of occurrence of frequencies. The frequency pattern provides information about the possible number of ongoing processes in the cell and their time constants. Unfortunately, there are redundancies in the experimental data of DRT analysis which means that a measured frequency pattern can fit to several equivalent circuit models (ECM) but it is not possible to figure out which one describes it at best. That is why we want to follow a different approach: before analyzing experimental DRT data, a database consisting of simulated DRT spectra from very simple to more complex ECMs should be set up in which the description of the underlying physical process (in theory) in the cell is known. Then we would like to clarify which combination of the theoretical spectra fit at best to our experimental data and whether the selection makes sense with respect to the experimental parameters used.

Your Profile:

Student in the field of Physics, Chemistry, Computer Science or a relevant disciplinePrevious experience in programming especially of the following language is desirable but not necessarily required: PythonKnowledge on electrochemistry can be helpfulExcellent cooperation and communication skills and ability to work as part of a teamFluent in the English language

We offer:

An international environment and an excellent infrastructure in one of the biggest research centers within EuropeA contract as student assistant is possible

Please apply via recruiter’s website.

Quote Reference: Helmholtz-2019M-018