Alkaline polymer electrolyte membranes for fuel cell applications

Abstract

In this review, we examine the most recent progress and research trends in the area of alkaline polymer electrolyte membrane (PEM) development in terms of material selection, synthesis, characterization, and theoretical approach, as well as their fabrication into alkaline PEM-based membrane electrode assemblies (MEAs) and the corresponding performance/durability in alkaline polymer electrolyte membrane fuel cells (PEMFCs). Respective advantages and challenges are also reviewed. To overcome challenges hindering alkaline PEM technology advancement and commercialization, several research directions are then proposed.

Performance Assessment of a Polymer Electrolyte Membrane Electrochemical Reactor Under Alkaline Conditions − a Case Study With the Electrooxidation of Alcohols

“…Simultaneously, the reduction of O2 to OH -anions as shown in reaction 4 represents the cathodic reaction which is the responsible for the supply SEM and XPS analysis were performed for both FAA and 4VP/CS:PVA membranes after electrooxidations and no remarkable difference were observed compared to morphology and surface chemistry results of fresh membranes. Alkaline PEM suffers from a hydroxide/carbonate/bicarbonate equilibrium [53][54][55]. Such reactions reduce the pH of solution, providing a loss in the alcohol electrooxidation performance.…”

“…Recently, significant efforts are being focused on the production and characterisation of new alkaline anion exchange membranes (AAEMs) as alternative to acidic media, and the commonly used cationic membrane as SPE in a fuel cell [15,16] or direct alcohol fuel cells [17], to mention only a few examples. The use of AAEMs in alkaline media mainly benefits from the kinetic enhancement of the electrochemical oxygen reduction reaction (ORR); the organic fuels oxidation being favoured at alkaline pH; the utilisation of non-noble metals as electrode materials and the use of membranes without perfluorinated ionomers.…”

Effect of gas diffusion electrode parameters on anion exchange membrane fuel cell performance

“…Compared with conventional AFCs, AAEMFCs are superior in automotive application, owing to: (1) the elimination of electrolyte weeping, (2) reduced reactant crossover, (3) potentially simplified water management, as water is produced at the anode and consumed at the cathode, (4) a larger repertoire of effective catalytic materials, and (5) potentially reduced corrosion [2,[5][6][7]. To fully realize these advantages, extensive efforts have been made to explore new AEMs/ionomers using novel synthesis methods, a direction which has been most often identified as an important route in advancing the field [1,[8][9][10][11][12][13]. Unfortunately, AEM use requires new electrode design and raises new fabrication challenges, and little work on the electrode fabrication technology can be found in previous publications [14][15][16].…”

“…Recently, alkaline fuel cells (AFCs) have attracted a resurgence of interest for application involving H2 [1][2][3][4]. In particular, alkaline anion exchange membrane fuel cells (AAEMFCs), which use an alkaline anion-exchanged membrane (AEM) instead of a traditional liquid electrolyte, appear to be a potentially useful technique.…”

Desenvolvimento de membranas aniônicas obtidas por enxertia via irradiação para aplicação em células a combustível alcalinas

“…Como alternativa para melhorar a condutividade iônica, geralmente a membrana necessita de índices de capacidade de troca iônica (IEC) altos, o que por sua vez, pode causar modificações na membrana como, excessiva absorção de água ocasionando redução e, em alguns casos, a perda das propriedades mecânicas. (ZHOE et al, 2015;Wang et al, 2013;CHENG et al, 2015;VARCOE et al, 2014) A estabilidade química, mecânica e térmica das membranas aniônicas, dependem da natureza dos grupos funcionais capazes de transportar os ânions hidroxilas e também da cadeia do polímero base. Alem disso, as condições de operação da célula, temperatura e alcalinidade do meio (pH básico).…”