Fuel cells convert chemical energy directly into electrical energy with high efficiency and low emission of pollutants. However, before fuel-cell technology can gain a significant share of the electrical power market, important issues have to be addressed. These issues include optimal choice of fuel, and the development of alternative materials in the fuel-cell stack. Present fuel-cell prototypes often use materials selected more than 25 years ago. Commercialization aspects, including cost and durability, have revealed inadequacies in some of these materials. Here we summarize recent progress in the search and development of innovative alternative materials.

Materials for fuel-cell technologies

A comprehensive review on PEM water electrolysis

Over the past 30 years, significant commercial and academic progress has been made on Li-based battery technologies. From the early Li-metal anode iterations to the current commercial Li-ion batteries (LIBs), the story of the Li-based battery is full of breakthroughs and back tracing steps. This review will discuss the main roles of material science in the development of LIBs. As LIB research progresses and the materials of interest change, different emphases on the different subdisciplines of material science are placed. Early works on LIBs focus more on solid state physics whereas near the end of the 20th century, researchers began to focus more on the morphological aspects (surface coating, porosity, size, and shape) of electrode materials. While it is easy to point out which specific cathode and anode materials are currently good candidates for the next-generation of batteries, it is difficult to explain exactly why those are chosen. In this review, for the reader a complete developmental story of LIB should be clearly drawn, along with an explanation of the reasons responsible for the various technological shifts. The review will end with a statement of caution for the current modern battery research along with a brief discussion on beyond lithium-ion battery chemistries.

30 Years of Lithium-Ion Batteries.

A review was presented to demonstrate a historical description of the synthesis of light-emitting conjugated polymers for applications in electroluminescent devices. Electroluminescence (EL) was first reported in poly(para-phenylene vinylene) (PPV) in 1990 and researchers continued to make significant efforts to develop conjugated materials as the active units in light-emitting devices (LED) to be used in display applications. Conjugated oligomers were used as luminescent materials and as models for conjugated polymers in the review. Oligomers were used to demonstrate a structure and property relationship to determine a key polymer property or to demonstrate a technique that was to be applied to polymers. The review focused on demonstrating the way polymer structures were made and the way their properties were controlled by intelligent and rational and synthetic design.

Synthesis of Light-Emitting Conjugated Polymers for Applications in Electroluminescent Devices

The state-of-the-art of polymer electrolyte membrane fuel cell (PEMFC) technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80 °C. Some of the key issues and shortcomings of the PFSA-based PEMFC technology are briefly discussed. These include water management, CO poisoning, hydrogen, reformate and methanol as fuels, cooling, and heat recovery. As a means to solve these shortcomings, high-temperature polymer electrolyte membranes for operation above 100 °C are under active development. This treatise is devoted to a review of the area encompassing modified PFSA membranes, alternative sulfonated polymer and their composite membranes, and acid−base complex membranes. PFSA membranes have been modified by swelling with nonvolatile solvents and preparing composites with hydrophilic oxides and solid proton conductors. DMFC and H2/O2(air) cells based on modified PFSA membranes have been successfully operated at temperatures up to 120 °C under ambient pressure...

/pdf/approaches-and-recent-development-of-polymer-electrolyte-1glbhokzz9.pdf

Approaches and Recent Development of Polymer Electrolyte Membranes for Fuel Cells Operating above 100 °C

Recently, much effort has been devoted to the development of battery separators for lithium-ion batteries for high-power, high-energy applications ranging from portable electronics to large-scale energy storage for power grids. The separator plays a key role in battery construction because it functions as the physical barrier to prevent electronic contact between the two electrodes and at the same time serves as an electrolyte reservoir, facilitating the ionic conduction. The purpose of this Review is to describe the requirements and properties of membrane separators for lithium-ion batteries, the recent progress on the different types of separators developed, and the manufacturing methods used for their production. Specifically the large-scale manufacturing processes are highlighted along with the processing parameters that affect their properties. The outlook and future directions regarding the development of advanced separator technologies are also discussed.

Separators for Lithium‐Ion Batteries: A Review on the Production Processes and Recent Developments

Polybenzimidazole (PBI) and polysulfone (PSF) compose an immiscible polymer pair; the introduction however of functional groups such as sulfonate groups in the polymeric chain of PSF resulted in the formation of miscible blends with PBI. The miscibility behavior of a series of blends of PBI with sulfonated PSF (SPSF) at various sulfonation levels has been studied by dynamic mechanical analysis (DMA), FT-IR, and FT-Raman spectroscopy. DMA has shown that the sulfonation degree as well as blend composition controls the miscibility behavior of the studied system. In that respect, partially miscible or miscible blends were obtained when the sulfonation level is higher than 10 mol %. Since both polymers exhibit functional groups, which could participate in specific interactions, this possibility has been examined by FT-IR analysis. In absorption FT-IR spectra of PBI−SPSF specimens with high sulfonation degree and high PBI content, band shifts associated with the NH and sulfonate groups are accounted for the ind...

Miscibility Behavior of Polybenzimidazole/Sulfonated Polysulfone Blends for Use in Fuel Cell Applications

Polymeric membranes from blends of sulfonated polysulfones (SPSF) and polybenzimidazole (PBI) doped with phosphoric acid were developed as potential high-temperature polymer electrolytes for fuel cells and other electrochemical applications. The water uptake and acid doping of these polymeric membranes were investigated. Ionic conductivity of the membranes was measured in relation to temperature, acid doping level, sulfonation degree of SPSF, relative humidity, and blend composition. The conductivity of SPSF Was of the order of 10 3- S cm 1 . In the case of blends of PBI and SPSF it was found to be higher than 10 -2 S cm -1 . Much improvement in the mechanical strength is observed for the blend polymer membranes, especially at higher temperatures. Preliminary work has demonstrated the feasibility of these polymeric membranes for fuel-cell applications.

/pdf/development-and-characterization-of-acid-doped-48urnnclmv.pdf

Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells

New polymer electrolytes based on blends of sulfonated polysulfones with polybenzimidazole

A new high-molecular-weight, soluble, wholly aromatic polyether bearing polar pyridine and phosphinoxide groups along the main chain is presented. This easily processable polyether presents excelle...

Valadoula Deimede

Papers

Separators for Lithium‐Ion Batteries: A Review on the Production Processes and Recent Developments

Miscibility Behavior of Polybenzimidazole/Sulfonated Polysulfone Blends for Use in Fuel Cell Applications

Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells

New polymer electrolytes based on blends of sulfonated polysulfones with polybenzimidazole

Novel Proton-Conducting Polyelectrolyte Composed of an Aromatic Polyether Containing Main-Chain Pyridine Units for Fuel Cell Applications