IS Thermal management of polymer electrolyte membrane fuel cells: A review of cooling methods, material properties, and durability

Proton exchange membrane (PEM) fuel cells are a promising electrochemical energy converter with an energy efficiency as high as 60%. Thermal management plays an important role in PEM fuel cell operation. In this review, recent progress in thermal management is summarized with in-depth discussion on the waste heat generation mechanisms, thermal analysis, non-isothermal two-phase flow, cooling methods, cold starts, and relevant material properties and durability. Due to low operating temperature (similar to 80 degrees C), cooling PEM fuel cell stacks is much more challenging than traditional combustion engines. Various cooling methods are discussed and compared, along with the cooling strategies implemented in fuel cell electric vehicles (FCEVs). A challenging subject is to couple the thermal and water managements, such as non-isothermal two-phase flow, heat pipe effect, and two-phase interface dynamics. Cold start, i.e. startup from subfreezing condition, is discussed with in-depth analysis of key parameters regarding ice formation/melt and cold-start capability. Degradation, such as delamination and electrochemical active surface area (ECSA) loss during thermal, humidity and freeze/thaw cycles, is also briefly reviewed. Future work is proposed to further advance thermal management for PEM fuel cells.