Fuel Cell Technology: Reaching Towards Commercialization

A proton exchange membrane fuel cell (PEMFC) is an electrochemical device that converts the chemical energy of hydrogen and oxygen, with the aid of electrocatalysts, directly into electrical energy. After four decades of research and development, this device has reached the test and demonstration phase [1]. Typically, the analysis and design of PEMFCs are centered around the membrane-electrode assembly (MEA), which involves the characterization of the physical environment of the electrochemical reaction, the transport phenomena of gas (hydrogen, oxygen, water vapor, etc.), liquid water, proton and current, and the relationships between the fuel cell voltage, current, temperature, material (electrode, catalyst and membrane) properties and transport parameters.
Over the years, PEMFCs have been modeled at various levels of complexity with different focuses. Early work was mainly on the modeling of MEA using mechanistic methods [2] [3] [4] [5]. Attempts have been made to investigate the multispecies diffusion through the substrate and the diffusion layer of the electrode, the reaction kinetics in the catalyst layers, and proton and water transport through the membrane. The resultant models are generally governed by a set of complex partial differential equations. While the mechanistic models are built upon the rigorous mathematical descriptions of fundamental physics, they normally have very complicated expressions and often certain key physical parameters are difficult to quantify, which may in turn reduce the modeling effectiveness. Empirical modeling, by mapping the fuel cell voltage as a function of various contributing variables [6] [7]