Thermal Investigations of Electrochemical Devices

Electrochemical devices are amongst the most promising systems for renewable and clean energy; despite this there are a number of challenges which have both hindered widespread commercialisation and resulted in safety concerns. Common amongst all electrochemical devices is the importance of temperature and thermal management. Here, the thermal properties of components and devices are examined using infrared thermal imaging, and complimentary techniques, to improve both the fundamental understanding and safety of a number of electrochemical systems, with a focus on fuel cells and batteries. A study investigating the stress distribution in solid oxide fuel cell anodes under imposed non-uniform temperature conditions is described, highlighting the potential for combining infrared imaging with complimentary techniques; in this instance, X-ray diffraction. This study is expanded to show the potential impact of the results on finite element analysis. Thermal imaging is combined with X-ray microtomography in order to describe the surface temperature effects associated with discharging a cylindrical Li-ion battery. Here the internal structure of the cell is seen to have a major impact on the temperature variation observed. Advanced thermal imaging techniques are described with a diagnostic entitled electro-thermal impedance spectroscopy, in addition to the first reported use of lock-in thermography on a Li-ion battery. The impact of the work is highlighted, where appropriate detailing the potential incorporation of the diagnostic and experimental techniques in novel areas, whilst also considering the relevance to existing methodologies and mechanisms