TY - JOUR
T1 - Well-designed polyphenylene PEMs with high proton conductivity and chemical and mechanical durability for fuel cells
AU - Liu, Fanghua
AU - Miyatake, Kenji
N1 - Funding Information:
We thank Dr Akihiro Masuda of Toray Research Center for cross-sectional SEM images. This work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO), the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, through Grants-in-Aid for Scientific Research (18H05515), Japan Science and Technology (JST) through SICORP (JPMJSC18H8), JKA promotion funds from AUTORACE, the thermal and electric energy technology foundation and the China Scholarship Council (CSC).
Publisher Copyright:
© 2022 The Royal Society of Chemistry.
PY - 2022/2/14
Y1 - 2022/2/14
N2 - For highly proton conductive and durable proton exchange membranes, we designed and synthesized a new series of sulfonated polyphenylene ionomers (SPP-TFP) containing trifluoromethyl substituents with different ion exchange capacities (IEC). The resulting ionomers had high molecular weight (Mn = 51.2-123.4 kDa and Mw = 96.1-556.1 kDa) with reasonable polydispersity (3.8-5.4). The ionomers were highly soluble in some organic solvents such as DMSO and ethanol and provided bendable and ductile membranes by solution casting. The SPP-TFP-3.5 membrane exhibited the best balanced properties as proton exchange membranes; the proton conductivity was 7.5 mS cm−1 at 20% RH and 80 °C and the maximum strain was 155 ± 5%. The fuel cell performance of the SPP-TFP-3.5 membrane was comparable with that of the Nafion NRE 211 membrane. Furthermore, in the accelerated combined chemical and mechanical durability test based on wet/dry cycling at open circuit voltage (OCV) at 90 °C supplying H2 (anode) and air (cathode), the SPP-TFP-3.5 membrane (9847 cycles and 46.5 h) outperformed Nafion NRE 211(8788 cycles and 41.5 h). Furthermore, compared with Nafion NRE 211 (46.7 μV h−1 of average decay), SPP-TFP-3.5 showed negligible change in the cell voltage at 0.15 A cm−2 under 90 °C and 30% RH (air/H2) for 300 h. Such high durability and performance in practical fuel cells have not been reported for aromatic ionomer membranes.
AB - For highly proton conductive and durable proton exchange membranes, we designed and synthesized a new series of sulfonated polyphenylene ionomers (SPP-TFP) containing trifluoromethyl substituents with different ion exchange capacities (IEC). The resulting ionomers had high molecular weight (Mn = 51.2-123.4 kDa and Mw = 96.1-556.1 kDa) with reasonable polydispersity (3.8-5.4). The ionomers were highly soluble in some organic solvents such as DMSO and ethanol and provided bendable and ductile membranes by solution casting. The SPP-TFP-3.5 membrane exhibited the best balanced properties as proton exchange membranes; the proton conductivity was 7.5 mS cm−1 at 20% RH and 80 °C and the maximum strain was 155 ± 5%. The fuel cell performance of the SPP-TFP-3.5 membrane was comparable with that of the Nafion NRE 211 membrane. Furthermore, in the accelerated combined chemical and mechanical durability test based on wet/dry cycling at open circuit voltage (OCV) at 90 °C supplying H2 (anode) and air (cathode), the SPP-TFP-3.5 membrane (9847 cycles and 46.5 h) outperformed Nafion NRE 211(8788 cycles and 41.5 h). Furthermore, compared with Nafion NRE 211 (46.7 μV h−1 of average decay), SPP-TFP-3.5 showed negligible change in the cell voltage at 0.15 A cm−2 under 90 °C and 30% RH (air/H2) for 300 h. Such high durability and performance in practical fuel cells have not been reported for aromatic ionomer membranes.
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U2 - 10.1039/d1ta10480b
DO - 10.1039/d1ta10480b
M3 - Article
AN - SCOPUS:85128754833
SN - 2050-7488
VL - 10
SP - 7660
EP - 7667
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 14
ER -
