Reinforced Polymer Blend Membranes with Liposome‐Like Morphology for Polymer Electrolyte Membrane Fuel Cells Operating under Low‐Humidity Conditions

Abstract

Polymer electrolyte membrane fuel cells (PEMFCs) attract much attention as eco-friendly clean energy sources for transportation and stationary applications. [1,2] Proton-exchange membranes (PEMs) are essential components of these cells, acting as 1) separators to prevent the mixing of anode and cathode fuels and 2) conductors to aid the transport of protons from the anode to the cathode. Practically applicable PEMs should exhibit chemical, mechanical, and dimensional stability to fulfill the requirements of role 1) [3] and should maintain their proton conductivity even at low relative humidity (RH) to comply with the requirements of role 2). [1,4] The current state of the art is represented by perfluorosulfonic acid (PFSA) PEMs (e.g., Nafion), which exhibit high proton conductivity, superior mechanical properties, and chemical stability but suffer from high cost, high fuel permeability, and difficulty of structure/property modification. These drawbacks, together with the recent environmental and regulation issues regarding polyfluoroalkyl substances, have inspired the development of non-PFSA PEMs. [5] Sulfonated hydrocarbon-based PEMs, which offer superior thermal stability, low cost, and versatility of polymer types and can be synthesized from a variety monomers, have been investigated as promising alternatives to conventional PEMs. [6] However, the low mechanical stability of these membranes as separators and their low performance as proton conductors (particularly under low-humidity conditions) present an obstacle to usage in practical fuel cells. [7][8][9] To date, several solutions, such as physicochemical bonding (e.g., cross-liking and hydrogen bonding) [10][11][12] and hydrophilic-hydrophobic phase separation (e.g., multi-block copolymers, [13,14] comb-type PEMs, [12,15] densely sulfonated, [16] and organic/inorganic composites [17] ), have been suggested to build well-defined proton-conducting channels and, thus, obtain high proton conductivity and mechanical strength at low RH. Among them, one of the most interesting and easily applicable strategies is the construction of organic-inorganic composite membranes with functionalized inorganic fillers via the modification of aromatic polymer membranes with a high degree of sulfonation (DS). [17]

Perspective: New directions in dynamical density functional theory

“…The relation to other relaxation models was briefly discussed in [109]. Finally, the MesoDyn software [110], which allows to simulate polymer systems based on DDFT, remains an important tool in the study of polymer dynamics [111][112][113][114][115].…”

Design and synthesis of triboelectric polymers for high performance triboelectric nanogenerators

“…On the other hand, polymer science has expanded quickly in the past century, starting from the fundamental understanding of polymerization in the 1920s 25 to creating materials that almost cover all aspects in current life, including plastic, rubber, fibre, coatings, composites, and adhesives. 26–28 In recent years, one of the key aspects of polymer research focuses on enriching the applications of polymers in the field of energy and electronic devices, such as capacitors or batteries, 29–34 fuel cells, 35,36 organic photovoltaics, 37–39 organic light emitting diodes, 40,41 and even polymer electronic skin. 42–44 Then, with the emergence of the TENG technique, polymers with excellent triboelectric properties can be further exploited as a kind of functional material to be applied in the field of self-powered sensing and distributed power generation.…”