Work at the IAM-ET

Field of studies:

Battery safety is an important criterium for the wide introduction of the application in the transportation sector. Especially the behaviour during thermal runaway events are an essential aspect for safety evalutions. The underlying processes of the self-heating of the cells are barely understood. The comprehension of these reaction mechanism can help to reduce the probability and the magnitude of thermalrunaway events.

Scientific Focus:

Experimental analysis of thermal degradation processes in lithium-ion batteries under abusive conditions via in situ gas analysis. For this battery parameters are varied and their impact during temperature induced stress tests up to 130°C investigated. For this in situ gas analysis with an online electrochemical mass spectrometer (OEMS) is combined with simultaneously acquired electrochemical data. Additionally, materials are electrochemically characterized after abuse and analyzed in post-mortem analysis by structural, chromatographic as well as chemical methods. With the results a degradation network with precise temperature ranges for reactions will be developed for lithium-ion batteries showing the impact of investigated species during.

Methods used:

• Electrochemical cyclization with impedance spectroscopy
• Online electrochemical mass spectrometry
• Gaschromatography-mass spectrometry