Overview of Impact of Electrode Catalyst Loadings on Thin Flexible Fuel Cell (TFFC) Performance

Thin Flexible Fuel Cell (TFFC) is a flat and flexible device without any rigid support capable of being integrated into portable electronics. TFFC uses hydrogen and oxygen as fuel to provide high volumetric and gravimetric energy densities capable of competing with battery technology as a power source. The group is currently investigating a TFFC with an air-breathing design that maximizes the cathode interface with ambient air. The current challenges of making TFFC commercialized are the cost and performance. Enhanced cell performance is critical for a competitive cost of the device. The group investigated the impact of catalyst loading on the cell performance to increase the overall performance of the device. The catalyst loading of the cathode electrode was varied while keeping the anode catalyst loading constant and vice versa. The effects of the various catalyst loadings were characterized using various analytical techniques. Polarization curves and Electrochemical Impedance Spectroscopy (EIS) were used to separate and quantify the sources of losses for the TFFC. Power curves provided the maximum power density of the device. Cyclic voltammetry (CV) was implemented to characterize the electrochemically active surface area (ECSA) and utilization of the various catalyst layers. Rotating Disc Electrodes (RDE) tests were performed for a direct assessment of the catalyst. We will report the results of these assessments and summarize the resulting guidance for optimizing catalyst loading on similar fuel cell structures.