Open AccessAmphiphilic Ti porous transport layer for highly effective PEM unitized regenerative fuel cells
Author(s) -
Ahyoun Lim,
Hui-Yun Jeong,
Yong Sik Lim,
Jin Young Kim,
Hee-Young Park,
Jong Hyun Jang,
YungEun Sung,
Jong Min Kim,
Hyun S. Park
Publication year - 2021
Publication title -
science advances
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.928
H-Index - 146
ISSN - 2375-2548
DOI - 10.1126/sciadv.abf7866
Subject(s) - proton exchange membrane fuel cell , amphiphile , porosity , materials science , layer (electronics) , chemical engineering , nanotechnology , fuel cells , chemistry , composite material , polymer , engineering , copolymer
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.