Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks

• We measured a stack's current distribution without current sensors inside the stack.
• All sensors are outlying the stack, the additional resistance within the stack is negligible.
• The improvement of the setup's conductivity increases the measurands by a factor five.
• We demonstrate the function with a local resolution of 25% of the total cell area.
• We prove an excellent correlation of fuel cell simulation results and our measurements.

In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents.