In situ monitoring of high-temperature proton exchange membrane fuel cell stack using flexible micro temperature and voltage sensors

Internal local temperature and voltage not only affect reactions that occur in a membrane electrode assembly (MEA); they can also cause dehydration of the MEA in the electrochemical process that occurs in a proton exchange membrane fuel cell (PEMFC) stack, affecting its performance. In this work, micro-electro-mechanical systems (MEMS) are utilized to develop novel integrated micro sensors for use in high-temperature proton exchange membrane fuel cell stack, and integrated micro temperature and voltage sensors on stainless steel foil as a flexible substrate. These micro sensors can measure temperature and voltage data simultaneously and have the following advantages over other sensors: (1) they are small, (2) they are highly sensitive, (3) they can be batch-produced, (4) they can be placed anywhere to make measurements in situ.In this work, six micro sensors are embedded in the flow field of a high-temperature fuel cell stack and used to monitor local temperature and voltage in situ given various operating parameters. The results demonstrate that embedding micro sensors do not affect on cell performance and that the temperature and voltage distribution are non-uniform in a high-temperature fuel cell stack.

► Home-made micro-sensors can be placed anywhere in high temperature PEMFC stack.
► Micro-sensors are small, highly sensitive, flexible and in situ measurement.
► In situ diagnosis local temperature and voltage information of a high temperature PEMFC stack.