LAUSR

Abstract To improve the cold start performance of polymer electrolyte fuel cells (PEFCs), a novel microporous layer (MPL) with planar-distributed wettability, in which hydrophilic and hydrophobic rows are arrayed alternately in the in-plane direction, is proposed and examined. Since freezing occurs near the MPL and catalyst layer (CL) interface, which inhibits continued power generation, the reduction of water on the CL is important. Based on liquid exclusion of the hydrophobic area, liquid movement toward and absorption into the hydrophilic area should occur. As a result, extension of the temperature range for continuous operation at lower temperature and improvement of operational time of the PEFC at sub-freezing temperature (−4.2 °C to −10.0 °C) are achieved and no performance degradation occurs at 60–80 °C.