Outstanding proton conductivity over wide temperature and humidity ranges and enhanced mechanical, thermal stabilities for surface-modified MIL-101-Cr-NH_(2)/Nafion composite membranes  

作　　者：Xu Li Dongwei Zhang Si Chen Yingzhao Geng Yong Liu Libing Qian Xi Chen Jingjing Li Pengfei Fang Chunqing He 

机构地区：[1]Key Laboratory of Nuclear Solid-State Physics Hubei Province,School of Physics and Technology,Wuhan University,Wuhan,430072,China [2]School of Nuclear Technology and Chemistry&Biology,Hubei University of Science and Technology,Xianning,437100,China [3]Guangdong Key Laboratory for Hydrogen Energy Technologies,School of Materials Science and Hydrogen Energy,Foshan University,Foshan,528000,China

出　　处：《Green Energy & Environment》2024年第11期1734-1746,共13页绿色能源与环境（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)(Nos.12075172,12375288,12205089,and 12105048);National Key R&D Program of China(Grant No.2019YFA0210003);Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110817).

摘　　要：High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH_(2)(PCP-MCN),a kind of hybrid metal-organic framework,which exhibits a superior proton conductivity.PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes.Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated.Significant enhancement in proton conduction for PCP-MCN around 55℃ is interestingly found due to the thermal motion of the PCP molecular chains.Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains,i.e.,the formation of substantial acid–base pairs(-SO_(3)^(-)…^(+)H–NH-),which further improves compatibility between additive and Nafion matrix.At the same humidity and temperature condition,the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion.Proton conductivity(σ)over wide ranges of humidities(30-100%RH at 25℃)and temperatures(30-98℃ at 100%RH)for prepared membranes is measured.The s in PCPMCN/Nafion composite membranes is remarkably enhanced,i.e.0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98℃ and 100%RH,because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation–deprotonation processes.The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN.In particular,when 3 wt.%PCP-MCN was added to Nafion,the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480,1.098 W/cm^(2) under 40%RH,100%RH at 60℃,respectively,guaranteeing it t

关 键 词：Nafion composite membrane Surface-modified MIL-101-Cr-NH_(2) Proton conductivity Single-cell performance 

分 类 号：TM911.4[电气工程—电力电子与电力传动]