The scientific community is focused on the development of inexpensive and high-performing membrane materials for proton exchange membrane (PEM) fuel cells (FCs). The major approach to reducing the cost of FCs, which is crucial for the widespread acceptance of FCs as energy sources for various practical applications, is reducing the cost of the membrane. Efforts are being made in the development of advanced polymeric materials, which will satisfy the technical and economic demands of the consumers. Because most alternative membranes are outperformed by Nafion membranes over an entire set of important properties, it may be worthwhile to compromise on certain parameters to develop alternative specialized membranes. This review presents the properties (mainly conductivity and chemical and mechanical stability) of modern solid polymer electrolytes (SPEs) for PEM FCs.

Review of Advanced Materials for Proton Exchange Membrane Fuel Cells

This critical review tersely and concisely reviews the recent development of the polymer electrolyte membranes and the relationship between their properties and affecting factors like operation temperature. In the first section, the advantages and shortcomings of the corresponding polymer electrolyte membrane fuel cells are analyzed. Then, the limitations of Nafion membranes and their alternatives to large-scale commercial applications are discussed. Secondly, the concepts and approaches of the alternative proton exchange membranes for low temperature and high temperature fuel cells are described. The highlights of the current scientific achievements are given for various aspects of approaches. Thirdly, the progress of anion exchange membranes is presented. Finally, the perspectives of future trends on polymer electrolyte membranes for different applications are commented on (400 references).

Advances in the high performance polymer electrolyte membranes for fuel cells.

Polymer-based materials with tunable nanoscale structures and associated microenvironments hold great promise as next-generation ion-exchange membranes (IEMs) for acid or alkaline fuel cells. Understanding the relationships between nanostructure, physical and chemical microenvironment, and ion-transport properties are critical to the rational design and development of IEMs. These matters are addressed here by discussing representative and important advances since 2011, with particular emphasis on aromatic-polymer-based nanostructured IEMs, which are broadly divided into nanostructured polymer membranes and nanostructured polymer-filler composite membranes. For each category of membrane, the core factors that influence the physical and chemical microenvironments of the ion nanochannels are summarized. In addition, a brief perspective on the possible future directions of nanostructured IEMs is presented.

Nanostructured Ion‐Exchange Membranes for Fuel Cells: Recent Advances and Perspectives

Composite membranes comprising a continuous polymer phase and a dispersed filler phase have revealed appealing potential in selective transport of molecules and ions. The multiphase characteristics of composite membranes provide more degrees of freedom to manipulate multiple interactions, tailor multiscale structures, and integrate multiple functionalities, compared to pristine polymer membranes. In this feature article, we have reviewed the various methods for the fabrication of composite membranes. In particular, we have thoroughly discussed two typical methods: the physical blending method and the sol–gel method. For each method, the major advances and challenges have been summarized. We have also tentatively delineated the new generation of composite membranes.

Recent advances in the fabrication of advanced composite membranes

Polyelectrolyte complex membranes for pervaporation, nanofiltration and fuel cell applications

Water retention is a pervasive issue in agriculture and industry. Inspired by the water-storage mechanisms in plant cells, three kinds of polymeric microcapsules (PMCs) with carboxylic acid, sulfonic acid, and pyridyl groups are prepared using distillation–precipitation polymerization. The size of the lumen of the PMCs may govern the static water uptake by holding water molecules in a free-water state, and the functional groups in the shell of PMCs may manipulate dynamic water release by holding water molecules in a bound-water state, thus yielding PMCs with high and tunable waterretention properties. Incorporation of PMCs into composite membranes gives rise to dramatically enhanced water-retention properties and proton-transfer pathway, and consequently increased proton conductivity by up to one order of magnitude over the control polymer membrane, under low relative humidity of 20%. This study may offer a facile and generic strategy to design and prepare a variety of materials with superior water-retention properties.

Enhanced Water Retention by Using Polymeric Microcapsules to Confer High Proton Conductivity on Membranes at Low Humidity

Enhancing proton conduction and methanol barrier performance of sulfonated poly(ether ether ketone) membrane by incorporated polymer carboxylic acid spheres

Shuang Jiang

Papers

Enhanced Water Retention by Using Polymeric Microcapsules to Confer High Proton Conductivity on Membranes at Low Humidity

Enhancing proton conduction and methanol barrier performance of sulfonated poly(ether ether ketone) membrane by incorporated polymer carboxylic acid spheres