Improvement in solid oxide fuel cell performance through design modifications: An approach based on root cause analysis

Performance of the solid oxide fuel cell (SOFC) is significantly affected by ohmic and concentration losses. The ohmic losses increase with reduction in macroscopic and microscopic contact area at the interfaces of different components. On the other hand, the concentration losses depend on the distribution of fuel and oxidant over the active area. Present work aims to investigate the performance improvement through design modifications obtained from root cause analysis. The influence of the interfacial resistance (ohmic), both, in terms of the external compression load, i.e., the interaction at the microscopic level and macroscopic contact area, is minimised. The effect of the uniformity of the flow distribution on the performance of the scaled up SOFC is analysed. To these objectives, the base configuration is modified and the influence of the different modifications on the electrochemical performance is studied. At 0.7 V, the performance is observed to be enhanced by 62% through minimization of the contact resistance between interconnect and electrode. It is further improved by 100% with an increase in the apparent contact area for a given cell. Additional 50% enhancement in performance is observed by achieving better uniformity in the flow distribution. Overall ∼212% enhancement in the performance is achieved with a design, which consists of all the modifications in one cell.