Lim, Ahyoun Jeong, Hui-Yun Lim, Youngjoon Kim, Jin Young Park, Hee Young Jang, Jong Hyun Sung, Yung-Eun Kim, Jong Min Park, Hyun S. 2024-01-19T15:30:28Z 2024-01-19T15:30:28Z 2021-09-04 2021-03 2375-2548 https://pubs.kist.re.kr/handle/201004/117366 Polymer electrolyte membrane unitized regenerative fuel cells (PEM-URFCs) require bifunctional porous transport layers (PTLs) to play contradictory roles in a single unitized system: hydrophobicity for water drainage in the fuel cell (FC) mode and hydrophilicity for water supplement in the electrolysis cell (EC) mode. Here, we report a high-performance amphiphilic Ti PTL suitable for both FC and EC modes, thanks to alternating hydrophobic and hydrophilic channels. To fabricate the amphiphilic PTL, we used a shadow mask patterning process using ultrathin polydimethylsiloxane (PDMS) brush as a hydrophobic surface modifier, which can change the Ti PTL's surface polarity without decreasing its electrical conductivity. Consequently, performance improved by 4.3 times in FC (@ 0.6 V) and 1.9 times in EC (@ 1.8 V) from amphiphilic PTL. To elucidate reason for performance enhancement, discrete gas emission through the hydrophobic channels in amphiphilic PTL was verified under scanning electrochemical microscopy. English AMER ASSOC ADVANCEMENT SCIENCE Amphiphilic Ti porous transport layer for highly effective PEM unitized regenerative fuel cells Article 10.1126/sciadv.abf7866 1 SCIENCE ADVANCES, v.7, no.13 SCIENCE ADVANCES 7 13 scie scopus 000633443600037 2-s2.0-85103518030 Multidisciplinary Sciences Science & Technology - Other Topics Article 연료전지 수전해 수소 전기화학 재생연료전지